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INDONESIANHIGHWAY CAPACITY MANUAL

PART - II INTERURBAN ROADS

NO. 05/T/Bt/1995

DIRECTORATE GENERAL OF HIGHWAYS

MINISTRY OF PUBLIC WORKS

INDONESIA HIGHWAY CAPACITY MANUAL 2 INTERURBAN ROADS AND MOTORWAYS

JANUARY 1995

TABLE OF CONTENTS

FOREWORDChapter 1 - 5 See HCM - 1 URBAN MANUAL

Chapter 6 INTERURBAN ROADS

Chapter 7 MOTORWAYS

INDONESIAN HIGHWAY CAPACITY MANUAL 2

TABLE OF CONTENTS

FOREWORD

Chapter 1-5 See HCM-1 URBAN MANUAL

Chapter 6 INTERURBAN ROADS

1. INTRODUCTION ...................................................................................... 6 – 32. METHODOLOGY ...................................................................................... 6 – 153. CALCULATION PROCEDURE FOR OPERATIONAL ANALYSIS AND DESIGN ............................................................................................ 6 – 27

STEP A: INPUT DATA .......................................................................... 6 – 28STEP B: ANALYSIS OF FREE FLOW SPEED .................................... 6 – 38STEP C: ANALYSIS OF CAPACITY ................................................... 6 – 47STEP D: LEVEL OF PERFORMANCE ................................................ 6 – 54

4. CALCULATION PROCEDURE FOR PLANNING ANALYSIS........... 6 – 605. WORKED EXAMPLES .............................................................................. 6 – 666. LITERATURE REFERENCES ................................................................... 6 – 87

Chapter 7 MOTORWAYS

1. INTRODUCTION ...................................................................................... 7 – 32. METHODOLOGY ...................................................................................... 7 – 83. CALCULATION PROCEDURE FOR OPERATIONAL ANALYSIS AND DESIGN ............................................................................................ 7 – 20

STEP A: INPUT DATA .......................................................................... 7 – 21STEP B: ANALYSIS OF FREE FLOW SPEED .................................... 7 – 28STEP C: ANALYSIS OF CAPACITY ................................................... 7 – 34STEP D: LEVEL OF PERFORMANCE ................................................. 7 – 39

4. CALCULATION PROCEDURE FOR PLANNING ANALYSIS ........ 7 – 455. WORKED EXAMPLES .............................................................................. 7 – 506. LITERATURE REFERENCES 7 – 57

FOREWORD

FOREWORD

The Directorate General of Highways (Direktorat Jenderal Bina Marga) has beenintroducing a “standardization” policy which endeavors to optimize investment, designs and construction methods for highways so as to obtain the most efficient use of available resources, and materials, as well as improvement of thr ability of Indonesian engineers. For this purpose, standard guidance regarding Methods of Works, Specification, and Procedure of Testing Materials in the aspects of Planning. Design, Construction,Operation and Maintenance have a high level of necessity in achieving a higher level of efficiency.

The need for an Indonesian Highway Capacity Manual was identified in 1986 by a joint committee of the Directorate General of Highways, the Indonesian Road Engineering,and the S2-STJR-ITB Programmer. The first phase of the Indonesian Highway CapacityManual study (IBRD Loan HSL No.3133-IND) had developed a Highway CapacityManual for different types of traffic facilities in urban and semi urban environments, and has been disturbed as an interim standard.

The second phase of the study started in January 1993 (IBRD Loan HSL No.3133-IND)produced a manual for interurban highways. The manual will make it possible to predict thefree flow speed, capacity and speed-flow relationship of a road section as a function ofgeometric design, pavement, environment, and traffic condition. The final report entitled"Indonesian Highway Capacity Manual Part-II", will be integrated with the manual from the first phase, in order to cover all types of urban and interurban traffic facilities.

Directorate General of Highways hereby expresses a sincere gratitude to all those whohave contributed to the development of the Indonesian Highway Capacity Manual, and any comments and suggestions will be most welcome.

Jakarta, January 1995

DIRECTORATE GENERAL OF HIGHWAYS

Director of Engineering,

Ir. Mohamad Anas Aly

STEERING COMMITTEE INDONESIAN HIGHWAY CAPACITY MANUAL

PHASE II - INTER URBAN ROADS

Chairman Ir. Syarifuddin Alambai Dit. Bipran

SecretaryIr. Yunius Hutabarat Dit. Bipran

Project Officer Ir. Palgunadi M.Eng.Sc. Dit. Binkot

Others Committee Members : Prof. Ir. T. Soegondo MSCE ITB S2 STJR Ir. Mohamad Anas Aly Dit. Bipran/Bintek Letkol (Pol) Drs. Juridis Darwis Dit. Lantas Polri Mayor (Pol) Drs. Endro Agung, M.Eng.Sc. Dit. Lantas Polri Ir. Naek Sembiring M.Sc. Ditjen. Perhub. Darat Ir. Gandhi Harahap M.Eng. Puslitbang Jalan Dr. Hermanto Dardak M.Eng.Sc. Biro Perencanaan Didik Rasidi, BE. Dit. Bipran Drs. Muchsin Asegaaf Dit. Bipran Ir. Yayan M.Eng.Sc. Dit. Bipran

Chapter 6

INTERURBAN ROADS

CHAPTER 6

INTERURBAN ROADS

TABLE OF CONTENTS

1. INTRODUCTION ................................................................................................6 – 3

1.1 SCOPE AND OBJECTIVES ..................................................................................6 – 31.2 ROAD CHARACTERISTICS ................................................................................6 – 51.3 DEFINITIONS AND TERMINOLOGY ................................................................6 – 71.4 LOCAL VERIFICATION ......................................................................................6 – 12

2. METHODOLOGY ...............................................................................................6 – 15

2.1 GENERAL APPROACH .......................................................................................6 – 152.2 VARIABLES ..........................................................................................................6 – 162.3 BASIC RELATIONSHIPS .....................................................................................6 – 192.4 GEOMETRIC CHARACTERISTICS ....................................................................6 – 232.5 OVERVIEW OF THE CALCULATION PROCEDURE ......................................6 – 25

3. CALCULATION PROCEDURE FOR OPERATIONAL ANALYSIS AND DESIGN .......................................................................................................6 – 27

STEP A: INPUT DATA ........................................................................................................6 – 28A-1: General data ...............................................................................................6 – 28A-2: Geometric conditions .................................................................................6 – 30A-3: Traffic conditions .......................................................................................6 – 34A-4: Side friction ................................................................................................6 – 37

STEP B: ANALYSIS OF FREE-FLOW SPEED ...............................................................6 – 38B-1: Base free-flow speed ..................................................................................6 – 39B-2: Free-flow speed adjustment factor FFVW for carriage way width .............6 – 41B-3: Free-flow speed adjustment factor FFVSF for side friction ........................6 – 42B-4: Free-flow speed adjustment factor FFVRC for road

function class and land use ........................................................................6 – 43B-5: Determination of free-flow speed for actual

conditions ...................................................................................................6 – 44B-6: Free-flow speed for specific grades ...........................................................6 – 45

STEP C: ANALYSIS OF CAPACITY ................................................................................6 – 47C-1: Base capacity .............................................................................................6 – 47C-2: Capacity adjustment factor FCW for carriageway

width ..........................................................................................................6 – 48C-3: Capacity adjustment factors for traffic conditions ..................................... 6 – 49

C-4: Capacity adjustment factor FSF for side friction ........................................6 – 50C-5: Determination of capacity for actual conditions .........................................6 – 51C-6: Capacity for specific grades ........................................................................6 – 52

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STEP D: LEVEL OF PERFORMANCE .............................................................................6 – 54D-1: Degree of saturation ....................................................................................6 – 54 D-2: Speed and travel time ..................................................................................6 – 55D-3: Degree of bunching (platooning) ................................................................6 – 57D-4: Speed and travel time for specific grades ...................................................6 – 58D-5: Evaluation of level of performance .............................................................6 – 59

4. CALCULATION PROCEDURE FOR PLANNING ANALYSIS ....................6 – 60

4.1 BASIC ASSUMPTIONS FOR DIFFERENT ROAD TYPES ................................6 – 604.2 ANALYSIS OF ROAD PERFORMANCE .............................................................6 – 63

5. WORKED EXAMPLES ........................................................................................6 – 66

5.1 CONVERSION INTO RADIANS/KM ...................................................................6 – 66 5.2 EXAMPLE-1: OPERATIONAL ANALYSIS OF A TWO-LANE

TWO-WAY ROAD .......................................................................6 – 675.2 EXAMPLE-2: PLANNING ANALYSIS ...............................................................6 – 76 5.3 EXAMPLE-3: OPERATIONAL ANALYSIS OF A SPECIFIC GRADE ............6 – 79

6. REFERENCES ……………………………………………………………….......6 – 87

APPENDIX 6:1 Calculation forms ………………………………………………. ..6 – 89

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HCM: INTERURBAN ROADS

1. INTRODUCTION

1.1 SCOPE AND OBJECTIVES

1.1.1. Definition and facility types

This Chapter presents procedures for the calculation of capacity and performance measures on interurban roads.

A road segment is defined as being interurban or as being urban/suburban as follows:

Urban/suburban road segments: Having continuous permanentdevelopment along all or almost all of its length, on at least one side ofthe highway, whether or not it is ribbon development. Highways in or near major urban centres of at least 100,000 population always come intothis category. Highways in urban areas of less than 100,000 population would also come into this category if they have continuous permanentroadside development.

Interurban road segments: Without continuous development on eitherside, though there may be some intermittent permanent development, such as restaurants, factories, or villages.

(Note: Small kiosks and stalls at the road edge do not constitutepermanent development).

Further useful indications of an urban or suburban area is the characteristic of morning and evening peaks in traffic flow, higher trafficflows in general and a change in traffic composition (with a higherpercentage of private cars and motor cycles, and a smaller percentage of heavy trucks in the traffic stream). A marked increase in peaking shouldmanifest itself in a change in (a more uneven) directional distribution of traffic, and so a highway segment boundary should be introduced between interurban and suburban segments (see sub-sections 1.1.3 and 1.1.4 below). Similarly, a marked change in flow should also prompt the introduction of a segment boundary. A further helpful (though notconclusive) indicator is the presence of a kerb: interurban highways are rarely kerbed.

If the road segment to be analysed does not conform to the abovedescription of an interurban road, then go to Chapter 5 on Urban Roads or, if the road is grade-separated with full control of access, to Chapter 7 on Motorways.

The interurban road types presented in this Chapter are as follows:- Two-lane two-way roads (2/2 UD) - Four-lane two-way roads- undivided (i.e. no median) (4/2 UD)- divided (i.e. with median) (4/2 D).

The Manual can also be used to analyse designs with more than four lanes.

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1.1.2. Application

The geometric characteristics of the road types used in this Chapter aredefined in Section 2.4.2 below. They are not necessarily related to the Indonesian functional road classification system (Undang-undang tentangJalan, No. 13, 1980), which was developed for a different purpose.

For each of the defined road types, the calculation procedures can be appliedfor:

- operational analysis, design and planning of roads in flat, rolling or hilly terrain;

- operational analysis of specific grades.

Although this Chapter is entitled 'Interurban roads', the procedures contained in it may be applied not only to national roads but also toprovincial and kabupaten roads. In fact they may be applied to any roadswhich are not urban/suburban, provided the characteristics of the roadfall within the ranges given in this Chapter.

1.1.3. Road segments

The procedures in the Manual are applied to calculations for individualsegments of a road. A road segment is defined as a length of road:

- between and unaffected by major intersections, and- having similar geometric design and traffic flow and composition along

its length.

Points where road characteristics change significantly automatically become the boundary of a segment even if there is no nearby intersection.The road characteristics of importance in this respect are discussed below.

Interurban road segments can generally be expected to be considerablylonger than urban and suburban road segments because geometric and other characteristics generally change less frequently and major junctions are much less closely spaced. They can be tens of kilometres in length.However it is important that segment boundaries are made wherevercharacteristics change significantly, even if the resulting segments are very much shorter than this.

Segment boundaries should be set where terrain type changes, even though other characteristics of geometry, traffic and environment (friction)remain the same. It is however not necessary to be concerned about minorchanges in geometry (e.g. carriage way width differences of less than 0.5 m), particularly if they are intermittent.

Specific grades are always separate segments.

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1.1.4. Urban areas and intersections along the road

Segment boundaries should be made where an interurban road is judged to have become an urban or suburban road (or vice versa), even if geometricor other characteristics have not changed, and the appropriate chapter of the Manual should be used for each segment.

Villages should not be considered to be urban areas, unless the road passesthrough the centres of towns in which the roadside characteristics meanthat the road conforms to the urban/suburban road definition given in Section 1.1.1. above. In such a case Chapter 5 on Urban and SuburbanRoads should be used, together if necessary with the appropriate chapterson other urban traffic facilities (Chapter 2 - Chapter 4).

Similarly, if an essentially interurban road encounters one or more majorintersections, especially if they are signalised, whether in an urban area or not, it is necessary to incorporate the effect of the intersection(s). This canbe done as follows:

- Calculate travel time, using the interurban road procedures, as if there was no disturbance from the intersection(s), i.e. do the analysis as if theintersection(s) did not exist ("unobstructed travel time").

- For each major intersection along the road, calculate delay, using appropriate procedures from Chapters 2 to 4 of this Manual.

- Add the intersection delay(s) to the unobstructed travel time, to obtain the overall travel time (and if necessary, convert to speed by dividing the overall distance (km) by the overall travel time (in hours)).

1.2 ROAD CHARACTERISTICS

The main characteristics of a road which will affect its capacity and its performance when loaded with traffic are identified below. Any point on a particular road where there is a significant change in geometric design,traffic flow characteristics or in roadside activities becomes the boundary of a road segment as described in Section 1.1.3. above.

1.2.1. Geometry

- Width of carriageway: capacity increases with carriageway width.

- Shoulder characteristics: capacity, and speed at a given flow, increasemarginally with increasing shoulder width. Capacity is reduced-if there are fixed obstructions close to the edge of the carriageway.

- Presence or absence of median (divided or undivided): well-designedmedians increase capacity. There may however be other reasons why a median is not preferred, e.g. lack of space, cost, access to roadside facilities etc..

- Vertical curvature: this has two effects, the more hilly the road, the slower the vehicles will travel on up grades (this is usually not compensated for on down grades) and also hill-brows reduce sight distance. These effects both reduce capacity and performance at a given flow.

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- Horizontal curvature: roads with many sharp bends require vehicles to travel slower than on straighter roads, in order to ensure that tyresmaintain safe contact with the road surface. Horizontal and vertical curvature may be expressed as a general terrain type (flat, rolling orhilly). They are often also related to sight distance class. Vertical and horizontal curvature are particularly important on two-lane two-wayroads.

- Sight distance: where sight distance is long, overtaking is easier and speed and capacity higher. Though dependent partly on vertical and horizontal curvature, sight distance also depends on the presence or absence ofobstructions to sight from vegetation, fences, buildings and so on.

1.2.2. Flow, composition and directional split

- Directional split of traffic: capacity is highest on undivided roads when the directional split is 50 - 50: that is to say when the flows are equal in both directions. Note that a directional split of, say, 70-30 is equivalentfor calculation purposes to a directional split of 30 - 7(l.

- Traffic composition: if flow and capacity are measured in veh/h, traffic composition will affect capacity. However, by measuring flow in light vehicle units (Ivu), as in this Manual, this effect has been accounted for.

1.2.3. Traffic control

Controls on speeds, heavy vehicle movements, parking, etc. will affect the capacity of the road.

1.2.4. Land use and roadside activities ("side friction")

The many activities in Indonesia at the roadside often conflict, sometimesseverely, with flow of traffic. The effects of these conflicts, ("side friction"), is given extra attention in this Manual in comparison toWestern manuals. The side friction items which have been found to primarily affect the capacity and performance of interurban roads are:

- pedestrians;- stopping public transport and other vehicles; - slow-moving vehicles (e.g becaks, horsecarts); - vehicles entering and leaving roadside premises.

To simplify their inclusion in the calculation procedures, these frictionalitems have also been described in relation to land use developmentcharacteristics along the road segment, as defined in Section 1.3. below.

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1.2.5. Road function

Road functional class (arterial, collector, local) can affect free-flow speed as the functional class tends to reflect the type of trips taking place on the road. There is a strong correlation between road functional class and administrative road class (national, provincial, kabupaten). If there is any doubt about the functional class of a particular road, the administrative class could be used as an indicator.

1.2.6. Driver and vehicle population

Driver behaviour and vehicle population (the age, power and condition of vehicles within each vehicle class, as distinct from vehicle composition)differ between different parts of Indonesia. Older vehicles of a given type,or less urgent driver behaviour could result in lower capacity andperformance. These effects cannot be directly measured but could be accountedfor by local verification of key parameters, as recommended in Section 1.4.

1.3 DEFINITIONS AND TERMINOLOGY

NOTATION TERM DEFINITION

General performance measures

C CAPACITY(Ivu/h)

Maximum sustainable (stable) trafficflow over a road section under given conditions (e.g. geometric design,environment, traffic etc.).

DS DEGREE OFSATURATION

Ratio of flow to capacity.

TT TRAVEL TIMEJOURNEY TIME

Total time (h, min or s) required totraverse a given length of road, including all stopped time delay.

V TRAVEL SPEEDJOURNEY SPEED

Average speed (km/h) computed asthe length of road divided by the traveltime along it.

FV FREE FLOW SPEED (1)The theoretical average speed (km/h) of traffic when density is zero,i.e, there are no vehicles present.

(2)Speed (km/h) of a vehicle which isnot restrained by any other vehicles (i.e.speed at which drivers feel comfortable travelling under the geometric,environmental, and traffic controlconditions existing on a road segmentwith no other traffic).

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B BUNCHING(PLATOONING)

Traffic condition when vehicles are driving in a queue (platoon) at similar speedbecause of restraint by a leading vehicle(platoon leader). (Note: leading headway < 5 sec).

DB DEGREE OF BUNCHINGRatio of flow of vehicles traveling inplatoons to total flow.

Geometric conditions

WC CARRIAGEWAYWIDTH

Width (m) of the roadway used for trafficflow, excluding shoulders.

WCe EFFECTIVECARRIAGEWAYWIDTH

Carriageway width (m) available for trafficmovement, after any reduction due toparking, for example. (Note: Pavedshoulders are sometimes considered to bea part of the effective carriageway width).

WS SHOULDER WIDTH Width of the shoulder (m) adjacent to thecarriageway designed to provide space for. occasional stopping of vehicles, forpedestrians and slow-moving vehicles.

WSe EFFECTIVESHOULDERWIDTH

Width of the shoulder (m) actually availablefor use, after any reduction due toobstructions such as trees, roadside stalls,etc. (Note: See note above underEFFECTIVE CARRIAGE WAY WIDTH).

SHOULDERUSABILITY

Possibility to use the shoulder for vehicular movements (e.g travel, parking,emergency stops).

MEDIAN Area separating traffic directions on a road.

L ROAD LENGTH Length of road segment (km).

ROAD TYPE Road type defines the number of lanes anddirections on a road segment; for interurbanroads:- 2-lane 2-way undivided (2/2 UD)- 4-lane 2-way undivided (4/2 UD)- 4-lane 2-way divided (4/2 D)- 6-lane 2-way divided (6/2 D)- 2-lane 1-way (2/1)

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TERRAIN TYPE Terrain type is a description of the hilliness of the area through which a roadpasses and is defined by the total rise plus fall (m/km) and the total horizontalcurvature (rad/km) over the roadsegment; see Table 1.3:2. (Values inparentheses have been used to develop thegraphs for standard terrain types in the Manual):

Terraintype

descriptionVertical

CurvatureRise+fall(m/km)

HorizontalCurvature:(rad/km)

F Flat < 10 (5) <1.0(0.25)

R Rolling 10 – 30 (25) 1.0 – 2.5 (2.00)

H hilly > 30 (45) > 2.5 (3.50)

Tabel 1.3:2 Terrain types

Note: The terrain definitions regarding rise and fall in Table 1.3:2correspond to those used in the BinaMarga IRMS. (The IRMS does notutilise horizontal curvature to defineterrain type). In "Spesifikasi Standaruntuk Perencanaan Geometrik Jalan Luar Kota (DGH 1990) TERRAINTYPE is defined by the transverseslope of the terrain perpendicular to the highway centreline (Flat: 0 - 9.9%, Rolling 10 - 24.9%, Hilly > 25%).

RFC ROAD FUNCTIONAL CLASS The functional class of a road asdefined by Undang-undang tentangJalan, No. 13, 1980: 1 Arterial2 Collector3 Local road

SDC SIGHT DISTANCE CLASS Sight distance is the maximum distanceatwhich a driver (of eye-height 1.2 m) isable to see another vehicle or a fixedobject of defined height (1.3 m). Sightdistance class is defined by thepercentage of the segment having sightdistance 300m; see Table 1.3:3.

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Sight distance class

% of segment with sight distance of at

least 300 mABC

> 70% 30 – 70%

< 30%

Tabel 1.3:3 Sight distance classes

LU LAND USE Development of land adjacent to the road. For calculation purposes land useis defined as the percentage of a roadsegment with permanent roadsidedevelopment in the form of buildings.

SF SIDE FRICTION Side friction is the impact on trafficperformance of roadside events on theroad segment, such as pedestrians(weight=0.6), stops made by public transport and other vehicles (weight0.8), vehicles entering and exitingroadside premises (weight 1.0), andslow-moving vehicles (weight 0.4).

SFC SIDE FRICTION CLASS See Table 1.3:4 for determination ofside friction class:

Side friction class

Code Weighted fre-quency of events(both sides)

Typical conditions

Very low LowMediumHighVery high

VLLMH

VH

< 50 50- 150 150 - 250250 - 350

> 350

Rural: agricultural or undeveloped Rural: some roadside buildings & activities Village: residential activitiesVillage: some market activities Almost urban: many market/businessactivities

Tabel 1.3:4 Side friction classes

Traffic composition

TRAFFIC ELEMENT Object or pedestrian being part of traffic

veh VEHICLE Traffic element on wheels.

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LV LIGHT VEHICLE Two-axle motor vehicle on four whells with an axle spacing of 2.0 – 3.0 m (including passenger car, oplet, micro bus, pick-up and micro truck according to Bina Marga Classification System)

MHV MEDIUM HEAVYVEHICLE

Two-axle motor vehicle with an axle spacing of 3.5-5.0 m (including smallbuses, 2-axle truck with six wheels according to Bina Marga classificationSystem)

LT LARGE TRUCK Three-axle trucks and truckcombinations with axle spacing (first tosecond axle) < 3.5 m (according to BinaMarga classification system).

LB LARGE BUS Two- or three-axle buses with an axle spacing of 5.0 - 6.0 m.

MC MOTOR CYCLE Motor vehicles with two or three wheels(including motorcycles and 3-wheeledvehicles according to Bina Margaclassification system).

UM UNMOTORISED VEHICLE Unmotorised traffic element on wheels(including becak, bicycles, horse-carriages and pushcarts according to BinaMarga classification system).

Traffic conditions

Q TRAFFIC FLOW Number of traffic elements passing a point on a road per unit of time, expressed inveh/h (Qveh) or lvu/h (QIvu).

SP DIRECTIONALSPLIT

Flow distribution (veh) between the directions of travel on a two-way road (calculated as ratio of flow in onedirection to total flow and expressed as the percentage of total flow in each direction, e.g. 60:40).

Calculaton conditions

C0 BASE CAPACITY(Ivu / h)

Capacity of a road segment for a predetermined (see Section 2.4.2) set of conditions (geometry, traffic flowpattern and environmental factors).

FCW CAPACITY ADJUSTMENT FACTOR FORCARRIAGEAWAY WIDTH

Adjustment factor for base capacity due to carriageway width.

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FCSP CAPACITY ADJUSTMENT FACTOR FOR DIRECTIONAL SPLIT

Adjustment factor for base capacitydue to directional split (undividedroads only.)

FCMC CAPACITY ADJUSTMENT FACTOR FORMOTORCYCLE TRAFFIC

Adjustment factor for base capacitydue to flow of motorcycle traffic.

FCSF CAPACITY ADJUSTMENT FACTOR FOR SIDE FRICTION

Adjustment factor for base capacitydue to side friction as a function ofshoulder width.

PC LVU FACTOR (CAPACITY)

Factor to convert a vehicular flow into an equivalent light vehicle flow forcapacity analysis.

PV LVU FACTOR(SPEED)

Factor to convert a vehicular flow into an equivalent light vehicle flow for speed analysis.

K AADT-FACTOR Conversion factor from AADT to peak hour traffic.

QD DESIGN HOURLYFLOW(veh/h)

Traffic flow (Ivu/h) used for planning: Q1, = AADT x K

FVo BASE FREE-FLOW SPEED(km/h)

Free-flow speed for a road segment for apredetermined (see Section 2.4.2) set ofconditions (geometry, traffic flow pattern and environmental factors),

FFVW SPEED ADIUSTMENT FACTOR FORCARRIAGEWAY WIDTH

Adjustment factor for base free-flow speed due to carriageway and shoulderwidth.

FFVSF SPEED AD IUSTMENT FACTOR FOR SIDE FRICTION

Adjustment factor for base free-flow speed due to side friction as afunction of shoulder width.

FFVRC SPEED AD IUSTMENT FACTOR FOR ROAD FUNCTIONAL CLASS

Adjustment factor for base free-flow speed due to road function class(arterial, collector or local) and landuse

1.4 LOCAL VERIFICATION

A number of factors specific to particular areas (such as driver and vehicle population) can affect the parameters given in this Manual. If they have theresources and appropriate expertise, users of the Manual are stronglyrecommended to measure key parameters (such as free-flow speed andcapacity) on a small number of representative sites within their study area,and to apply local adjustment factors on free-flow speed and capacity if theobtained values differ significantly from the values obtained by using this Manual.

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Four – lane divided road section

Four – lane undivided road section

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Two-lane undivided road section with broad gravel shoulders

Two-lane undevided road section in hilly terrain

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2. METHODOLOGY

2.1 GENERAL APPROACH

The calculation procedures given in the Manual are in some cases similar, at least in general form, to those in the 1985 U.S. HighwayCapacity Manual (US HCM) and its 1992 revisions. This is intentional, as users of this Manual may already be familiar with the US HCMprocedures. In detail however, the procedures are not the same. ThisChapter also uses some different variables. Where variables are in common, their values for Indonesian conditions are often quite different from the US HCM.

2.1.1. Types of calculations

The procedures given in this Chapter allow the calculation of thefollowing traffic characteristics for a given road segment:

- free flow speed; - capacity;- degree of saturation (flow/capacity);- speed at actual flow conditions;- degree of bunching at actual flow conditions;- traffic flow which can be accommodated by the given road segment

while maintaining a specified level of performance (defined by speed or bunching).

2.1.2. Levels of analysis

Procedures are given in this Chapter to enable analysis to be carried outat one of two levels:

- Operational analysis and design: The determination of theperformance of a road segment under existing or projected trafficdemand. The capacity can also be calculated, as can the maximumflow which can be carried while still maintaining a specified level ofperformance. The road width or number of lanes needed to carry a given flow of traffic while maintaining an acceptable performancelevel can also be calculated for design purposes. The effects on capacity and performance of a number of other design features, e.g. provision of a median or modifications to shoulder width, can also be assessed. This is the most detailed level of analysis.

- Planning: As for design, the objective is to estimate the number of lanes needed for a projected road, but the information on flow is likely to be given only as estimated AADT. The details of geometry and otherinputs can either be assumed or be based on recommended defaultvalues.

The methods used in operational analysis and design, and the methodsused in planning analyses are related and differ mainly in the level ofdetail in the inputs and outputs.

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Steps in planning analyses are very much simpler in most cases.

The procedures given in this Chapter also allow operational analysis to be carried out on one of two different types of road segments:

- General terrain segments: In this case the segment is allocated to a terraintype which reflects the general horizontal and vertical curvatureconditions of the segment - flat, rolling or hilly.

- Specific grades: A continuous steep section of road can act as a capacity'bottleneck' in both the uphill and downhill directions and can have performance effects which are not fully accounted for by subsuming thesteep section within a general terrain type. For this reason this Manualalso allows for the operational analysis of specific grades. The specificgrade procedures given in the Manual essentially only apply to two-lane two-way roads as gradient problems are usually worst on this road type. The procedures allow the effects of the grade to be calculatedas a basis for study of remedial actions, such as widening or providing acrawler lane.

2.1.3. Period of analysis

The capacity analysis of roads is performed for a peak one-hourperiod, and flows and mean speeds are expressed for this period. To use a full day (AADT) analysis period would be too coarse for operational analysisand design. At the other extreme, to use the peak 15 minutes within the peakhour would be too detailed. Throughout the Manual, flow is expressed asan hourly rate (Ivu/h), unless otherwise stated.

For planning, in which AADT is normally given, tables are provided to convert flows directly from AADT to performance measures and vice versa, under certain assumed conditions.

2.1.4. Divided and undivided roads

For undivided roads, including undivided motorways, all analyses (otherthan the analysis of specific grades) are carried out on both directions oftravel combined, using one set of analysis forms. For divided roads, analysesare performed separately for each direction of travel, as though each directionwere a separate one-way road.

2.2 VARIABLES

2.2.1. Traffic flow and composition

Throughout the Manual the traffic flow values (Q) reflect traffic composition,by expressing flow in light vehicle units (Ivu). All traffic flow values (perdirection and total) are converted to light vehicle units (Ivu) using empirically derived Ivu values for the following types of vehicles (seedefinitions in Section 1.3):

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- Light vehicles (LV) (including passenger cars, minibuses, pick-up trucks and jeeps).

- Medium heavy vehicles (MHV) (including two-axle trucks and smallbuses).

- Large buses (LB).- Large trucks (LT) (including three-axle trucks and truck combinations).

The effect of the presence of motorcycles is accounted for by means of amotorcycle adjustment factor, and the effect of the presence of unmotorisedvehicles is included as a separate event in the side friction adjustmentfactor.

Two sets of Ivu values with different criteria for equivalency are used:

- Speed-based Ivu values based on the relative impact on light vehicle speed of adding different types of vehicles into the traffic stream.

- Capacity-based Ivu values based on the relative impact on capacity of different vehicle types.

2.2.2. Free flow speed

Free flow speed (FV) is defined as the speed at flow level zero,corresponding to the speed a driver would choose if he/she was driving amotor vehicle which was not restrained by any other motor vehicles on the road (i.e. at flow = 0).

Free flow speeds have been observed by field data collection, from which the relationship between free flow speed and geometric and environmental conditions have been determined by means of regression.The free flow speed for light vehicles has been chosen as the base criterion for the performance of a road segment at flow = 0. Free flow speeds for medium heavy vehicles, large buses and large trucks are also given for reference (for definitions see Section 1.3). The free flow speedfor a passenger car is typically 10-15% higher than that for other types of light vehicles.

The equation for determination of free flow speed has the following general shape:

FV = FV0 + FFVW + FFVSF + FFVRC

where:FV = Free flow speed for light vehicles for the actual conditions

(km/h).FVo = Base free flow speed for light vehicles for the studied road and

terrain type, for ideal conditions (pre-defined, see Section 2.4below).

FFVW = Adjustment factor for road width (km/h).FFVSF = Adjustment factor for side friction conditions and shoulder

width (km / h).FFVRC = Adjustment factor for road functional class and land use

(km/h).

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2.2.3. Capacity

Capacity is defined as the maximum flow past a point on the road thatcan be sustained on an hourly basis under prevailing conditions. Fortwo-lane two-way roads capacity is expressed as a two-way flow (bothdirections combined), but for multi-lane roads the flow capacity is separated per direction of travel and expressed as capacity per lane.

Motorcycles are not treated as part of the traffic flow as described in Section 2.2.1, but as a separate factor which causes a reduction of capacity as described in Section 22.1 above.

Capacity values have been observed by field data collection whenever possible. Due to the lack of sites with flows near to the capacity of theroad segment itself (as distinct from the capacity of intersections along theroad), capacity has also been estimated theoretically by assuming amathematical relationship between density, speed and flow, see Section2.3.1 below. The capacity (C) is expressed in light vehicle units (Ivu), see below.

The basic equation for determination of capacity is as follow:

C = Co x FCw x FCSP x FCMC x FCSF

where:C = actual capacity (Ivu/h)Co = base (ideal) capacity for predefined (ideal) conditions (Ivu/h)FCw = road width adjustment factor FCSP = directional split adjustment factor (only for undivided roads)FCMC = motorcycle traffic adjustment factorFCSF = side friction and shoulder adjustment factor

2.2.4. Degree of saturation

Degree of saturation (DS) defined as the ratio of flow to capacity, is used as a key factor in the determination of the level of performance of an intersection. This is a widely used measure to indicate whether a roadsegment is expected to have capacity problems or not.

DS = Q/C

For analysis of the level of performance regarding speed, DS is calculated using Q and C and normally expressed in speed-based lvuvalues. For analysis of degree of bunching (DB), DS is calculated using flow and capacity expressed in capacity-based Ivu values.

2.2.5. Speed

The Manual uses travel speed (synonymous with journey speed) as themain measure of performance of road segments, since it is easy to understand and to measure, and is an essential input to road user costs in economic analysis. Travel speed is defined in this Manual as the space mean speed of light vehicles (LV) over the road segment:

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V = L/TTwhere:V = space mean speed of LV (km/h)L = length of segment (km)TT = mean travel time of LV over the segment (h)

2.2.6 Degree of bunching

A further useful indicator of the level of performance of a road segment is the degree of bunching that occurs, i.e. the ratio of flow of vehiclestravelling in platoons to total flow. In this Manual a platoon is defined as a procession of vehicles travelling behind one another with the leadingheadway (front axle to front axle of preceding vehicle) of each vehicle,except the first vehicle in the platoon, being s 5 seconds. Motorcycles,threewheeled vehicles and unmotorised vehicles are not considered to be parts of platoons. Degree of bunching (DB) is calculated using vehicles(excluding motorcycles) rather than light vehicle units.

2.2.7. Level of performance

In the US HCM road performance is represented by Level of Service (LOS): a qualitative measure reflecting drivers' perception of the qualityof driving. LOS is related in turn to a quantitative proxy measure, such asdensity or per cent time delay. The level of service concept wasdeveloped for use in the United States and the LOS definitions do not directly apply to Indonesia. This matter will be addressed in the nextphase of the HCM project (HCM-3). In this Manual speed, degree of saturation and degree of bunching are used as indicators for level of performance in this Chapter. Bunching may be taken to be a performancemeasure relating to LOS.

2.3 BASIC RELATIONSHIPS

2.3.1. Speed-flow-density relationships

The general principle underlying the capacity analysis of road segments is that speed decreases as flow increases. The speed decrease with unit flow increase is near constant at low and medium flows, but becomesgreater as flows get closer to capacity. Near capacity a small increase inflow results in a large decrease in speed.

Typical relationships between speed and density (calculated as Q/V) and between speed and flow are illustrated with the help of Indonesian fielddata for four-lane divided roads in Figures 2.3.1:1 and 2.3.1:2 and for two-lane two-way roads in Figures 2.3.1:3 and 2.3.1:4. A good mathematicalrepresentation of the relationships for multi-lane roads can often be obtained using the Single Regime model:

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V = FVx[1 - (D/D)(@-1)] 1/ (1-m)

D0/Di = [( 1-M)/ (@-m) ] 1/(@-1)where:D = Density (lvu/km) (calculated as Q/V) Dj = Density at completely "jammed" roadDo = Density at capacity@, m = Constants

For two-lane undivided roads the speed-flow relationship is often close to linear and can be represented by a simple linear model.

Data from the field surveys have been analysed to obtain typical speed flow-relationships for undivided and divided roads using these models.Flow on the horizontal axis has been replaced with degree of saturation(Q/C), and a number of curves have been traced representing differentfree-flow speeds in order to make the relationships generally applicableas shown in Section 3, Step D below.

Speeds are normally much lower in Indonesia than in developed countries at a given degree of saturation (flow/capacity = Q/C).

2.3.2. Relationship between degree of saturation and degree of bunching

Degree of bunching (DB) is a variable which is more sensitive to flow than speed, and so provides a reasonable approximation of level of performance. The same type of mathematical modelling as described forspeed above has been applied to develop generalised relationships between degree of saturation (DS) and degree of bunching (DB), see Figure 2.3.1:5 below.

Figure 2.3.1:1 Speed – density relationship for four-lane, divided road

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Figure 2.3.1:2 Speed – flow relationship for four-lane divided roads

Figure 2.3.1:3 speed – density relationship for two-lane undivided roads

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Figure 2.3.1:4 speed – flow relationship for two-lane undivided roads

Figure 2.3.1:5 Relationship between degree of saturation and degree of bunching forundivided, two-lane roads.

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2.4 GEOMETRIC CHARACTERISTICS

2.4.1. Terrain type

Three general terrain types (see definition in Section 1.3) recommended for use in operational as well as planning analysis:

Terrain type Rise + fall(m/km)

Horizontal curvature(rad/km)

Flat terrain <10 < 10

Rolling terrain 10-30 1.0-2.5

Hilly terrain >30 > 2.5

For special studies of 2/2 UD .roads the Manual also presents free flowspeed as a general function of vertical alignment expressed as rise+fall(m/km) and of horizontal alignment expressed as curvature (rad/km) for two-lane two-way roads.

2.4.2. Base cases for different road types

a) Two-lane, two-way undivided road (2/2 UD)

This road type encompasses all two-way roads with a carriageway width of up to 10.5 metres. For wider two-way roads the procedures for four-lane two-way undivided roads should be followed. (For roads close to 10.5 m in width, either set of procedures will give very similar results).

The standard road of this type is defined as follows:

- Seven metre effective carriageway width - Shoulders of effective width of 1.5 m on each side (unpaved

shoulders, not suitable for motor vehicle travel)- No median- Directional traffic split of 50 - 50 - Terrain type : flat- Land use : No roadside development- Side friction class : Very Low (VL)- Road functional class: Arterial road - Sight distance class : A

(See definition in Section 1.3).

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b) Four-lane, two-way undivided road (4/2 UD)

This road type encompasses all undivided two-way roads with lane markingas for four lanes and an undivided total carriageway width between 12 and 15 metres.


- Fourteen metre carriageway width- Shoulders of effective width of 1.5 m on each side (unpaved

shoulders, not suitable for motor vehicle travel);- No median- Directional traffic split of 50 - 50%- Terrain type : flat- Land use : No roadside development- Side friction class : Very Low (VL)- Road functional class: Arterial road - Sight distance class : A

c) Four-lane, two-way divided road (4/2 D)

This road type encompasses all two-way roads with two carriagewaysseparated by a median. Each carriageway has two marked lanes with awidth between 3.0 - 3.75 m.


- 2 x 7.0 metres carriageway width (excluding median width)- Shoulders of effective width of 1.0 m (measured as [(inner shoulder

width + outer shoulder width)/2] (see Figure A.2: in Section 3) for each carriageway (unpaved shoulders, not suitable for movingtraffic)

- Median- Terrain type : flat- Land use : No roadside development- Side friction class : Very Low (VL)- Road functional class: Arterial road - Sight distance class : A

d) Six-lane two-way divided roads (6/2 D) with the same general characteristics as described for 4/2 D above can also be analysed using this manual.

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2.5 OVERVIEW OF THE CALCULATION PROCEDURE

A flow chart of the calculation procedure for operational analysis and design purposes is presented in Figure 2.5:1 below. The different steps are described step-by-step in detail in Section 3.

The following forms are used for the calculations:

IR-1 Input data:- General conditions

- Road geometry

IR-2 Input data (cont.):- Traffic flow and composition

- Side friction

IR-3 Analysis for general road segments:- Free flow speed

- Capacity- Actual speed - Degree of bunching

IR-4 Analysis for specific grades- Free flow speed

- Capacity- Actual uphill speed

Note that Steps B, C and D (see Figure 2.5:1) are carried out separatelyfor divided roads, so in these cases two sets of Forms IR-3 and IR-4 areneeded, one for each direction.

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CALCULATION PROCEDUREOperational analysis and design

Figure 2.5:1 Overview of the calculation procedure for operational analysis anddesign.

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3. CALCULATION PROCEDURE FOR OPERATIONAL ANALYSIS AND DESIGN

The objectives of operational analysis for a particular road segment, under an existing or projected set of geometric, traffic and environmentalconditions, can be one or all of the following:

- to determine capacity;

- to determine the degree of saturation (DS = Q/C) associated with an existing or projected traffic flow;

- to determine the speed at which the road will operate.

- to determine the degree of bunching at which the road will operate.

The main objective of design analysis is to determine the required roadwidth to maintain a desired level of performance. This could mean carriageway width or number of lanes, but can also be to estimate the effect of a change in design, such as whether to construct a median or toimprove the shoulders. The calculation procedures used for operationalanalysis and for design are the same, and follow the principles outlined in Section 2.2.

This Chapter contains detailed step-by-step instructions to be carried out for the operational analysis or design, using the Forms IR-1, IR-2, IR-3 andIR-4. Blank forms for copying are given in Appendix 6:1.

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STEP A : INPUT DATA

STEP A-1: GENERAL DATA

a) Segmentation

Divide the road into segments. A road segment is defined as a length of road having similar characteristics along its length. Points where road characteristics change significantly become segment boundaries. Eachsegment is separately analysed. If several geometric alternatives (cases) are being explored for the segment, each case is given a unique code and is recorded into separate sets of input data forms (IR-1 and IR-2). Separateanalysis forms (IR-3 and if necessary IR-4) are also used for each case. Ifseparate time periods are to be analysed, then a separate case number must be assigned to each, and separate input data forms and analysis forms should be used.

The studied road segment should be unaffected by any major intersections or interchanges which might influence its capacity and level of performance.

Segments may be called 'general terrain segments' (the normal case) or'specific grades', see b) below.

b) Specific grades

At this stage it must be decided whether any part of the road is a specific grade which requires separate operational analysis. This could be the case if there is one or more continuous gradients along the road whichcause severe capacity or performance problems and where improvements toalleviate these problems are being considered (e.g. widening or providinga crawler lane). Each of such gradients could be designated a separatesegment and each analysed individually under the procedures for 'analysis of specific grades', given below. The segment would be from the base ofthe grade to its brow. Generally, specific grades should not be shorter than about 400m but have no upper length limit. However, specific grade segmentsshould be continuous upgrade (downgrade in the opposite direction) i.e. with no flat or downhill sections, and should have a gradient of at least 3 percent on average over the whole segment: the gradient need not be constantover the whole segment length. Short grades (up to about 1 km in length) wouldnormally only be analysed separately if very steep, while longer grades mayneed separate analysis even if less steep, because of their progressive speed-reduction effects, especially on heavy vehicles.

Even if a steep grade causes significant capacity and performance problems, it would not be designated a 'specific grade' if one or all of the following conditions apply:

- only a planning analysis is needed, not an operational analysis; - If there is no intention to consider modifications to geometric design to

alleviate the effects of the grade;- If the horizontal curvature is great enough to cause it, in the opinion of the

engineer, to be the single main determinant of capacity and performance,rather than the gradient.

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In these cases a separate 'specific grade' segment would not be defined and the gradient would be subsumed in the general analysis of the longer segment of which it forms a part, with gradient characteristics being accounted for by terrain type.

c) Segment identification data

Fill in the following general data in the top of Form IR-1:

- Date (day, month, year) and 'Handled by' (enter your name).

- Province in which the segment is situated.

- Link number (Bina Marga)

- Segment code (e.g Km 3.250-4.750)

- Segment between ... (e.g. Lembang and Ciater)

- Administrative road class (Toll road, National, Provincial orKabupaten)

- Road type: examples:

Four-lane two-way divided: 4/2 D Four-lane two-way undivided: 4/2 UD Two-lane two-way undivided: 2/2 UD Two-lane one-way: 2/1 (analysed as if it was one direction of a divided road).

- Segment length (e.g. 1.500 km)

- Road functional class (Arterial, Collector or Local)

- Time period to be analysed (e.g. Year 2000, a.m. peak hour)

- Case number (e.g. A2000:1)

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STEP A-2: GEOMETRIC CONDITIONS

a) Horizontal alignment and roadside development

Make a sketch of the road segment using the allocated space in Form IR-1. Make sure to include the following information:

- Compass arrow showing North.

- Km-posts or other objects used to identify the location of the road segment.

- Sketch of the horizontal alignment of the road segment.

- Arrows identifying Direction 1 (normally North- or East bound) andDirection 2 (normally South- or West bound).

- Names of the places which the road segment passes/connects.

- Major buildings or other roadside premises and land use.

- Intersections and entries/exits to roadside premises.

- Pavement markings such as centreline, no passing line, lane markings, pavement edge line etc.

Fill in the following information in the boxes under the figure:

- Horizontal curvature for the studied segment (radians/km) (ifavailable).

- Percentage of road segment on each side (A and B) with some kind of roadside development (farms, residential houses, shops etc), and the mean percentage of developed land use for both sides of the studied road segment.

b) Sight distance class

In the appropriate box under the horizontal alignment sketch, enter the percentage of road segment length with a passing sight distance greater than or equal to 300 m (if available). From this information the SightDistance Class (SDC) can be determined as shown in Table A-2:1 below,or it can be estimated by engineering judgement (if in doubt use defaultvalue = B). Enter the resulting SDC value in the box under the sketch of the horizontal alignment in Form IR-1.

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Sight distance class

% of segment with sight distance of at least 300 m

A > 70%B 30-70%C < 30%

Tabel A-2:1 Sight distance classes

Note: Sight distance relates to passing sight distance measured from the drivers' eye-height (1.2 m) to the height of an on-coming passenger vehicle (1.3 m).

c) Vertical alignment

Make a sketch of the vertical profile of the road in the same longitudinal scale as thesketch of the horizontal alignment above it. Indicate gradients in % ifavailable.

Fill in the information regarding the the total rise+fall of the segment (m/km)if available. If the segment is a specific grade, fill in information regarding average slope and length of the grade.

d) Terrain type

Fill in the information for terrain type by encircling the appropriate type (flat,rolling or hilly), using the information on horizontal curvature (rad/km) and onvertical rise and fall (m/km), together with Table A-2:2, to determine theterrain type.

Terraintype

Rise + fall(m/km)

Horizontal curvature (rad/km)

Flat <10 <1.0Rolling 10-30 1.00-2.5Hilly >30 >2.5

Table A-2:2 Terreain types

If the rise and fall or horizontal curvature information is not available, useengineering judgement or the IRMS terrain type for the Bina Marga link(s) into which the segment falls.

e) Road cross section

Make a sketch of the road cross section and indicate average effectivecarriageway width, median width, average effective (unobstructed) innerand outer shoulder widths (if divided road), roadside obstacles such astrees, ditches, etc. Observe that Side A and Side B are determined by thecross section reference line in the horizontal alignment sketch.

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Figure A-2:1 Illustration of the geometric terms used for a divided road.

Fill in the relevant geometric data for the studied segment in thespaces provided in the Table below the sketch. The geometric terms used are shown below. If a road only has a shoulder on one side, the average shoulder width is equal to half of the width of that shoulder. For a divided road the average shoulder width is calculated per direction as the average ofthe outer and inner shoulder widths.

If the shoulders have the same type of pavement and sub-structure as the carriageway, and have no vertical drop relative to the carriageway (see under Road surface condition below), the paved shoulder widths should be added to the carriageway width when the effective carriageway width iscalculated. (Consequently the same width should also be subtracted fromthe shoulder width when the effective shoulder width is calculated.

f) Road and shoulder surface condition

Fill in the following information:

Carriageway(s):

- Type of pavement (encircle the appropriate answer). - Pavement condition (encircle the appropriate answer).- Road roughness (IRI value) if available.

Shoulders: (Inner (median) and outer (roadside) if divided road)

- Surface type.- Mean vertical drop (difference between levels) between

carriageway and shoulders.- Shoulder usability classified as usable for traffic, parking, or

emergency stops only. The following guidelines are used for this classification:Traffic: The shoulder is > 2 m and has the same pavement

quality as the

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carriageway with no vertical drop. Parking: shoulder with lower quality pavement or gravel

surface with a width > 1.5 m and little vertical drop.

Emergency: A shoulder with very poor surface, and/or with a vertical drop relative to the carriagewaywhich makes it very uncomfortable to enter.

g) Traffic control conditions

Fill in information regarding applied traffic control measures on the studied road segment such as:

- Speed limit (km/h);- Stopping and parking restrictions; - Restrictions relating to specific vehicle types; - Special gross-weight and/or axle load restrictions; - Other traffic control devices/ordinances.

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STEP A-3: TRAFFIC CONDITIONS

Use Form IR-2 to record and reduce input data regarding light vehicle units (lvu), traffic flow and traffic composition.

a) Light vehicle units (lvu)

Two sets of lvu values for standard terrain types are given in the uppermost Table in Form IR-2 for Light vehicles (LV), Medium heavyvehicles (MHV), Large buses (LB) and Large trucks (LT) (including truckcombinations). The speed Ivu values are based on light vehicle speed as criteria for equivalency, the capacity Ivu values are based on a capacity equivalency for the total flow. The latter values are mainly used in analysisregarding degree of bunching, and when the degree of saturation (Q/C) using the lvu (speed) values exceeds 0.85. Motorcycle (MC) flow is recorded but is not included in the total flow. Unmotorised vehicle (UM) flow is recorded on Form IR-2 as a friction component (slow-movingvehicles).

For specific grades, miss out b) below and go directly to c).

b) Traffic flow and composition for general terrain

Two alternatives are presented below, depending upon the amount of detail available. Alternative 2 should be followed if possible.

ALTERNATIVE 1: Only AADT and traffic composition data is available.

1.a Enter the following input data in the appropriate boxes in Form IR-2:

- AADT (veh/day) for the studied year/case - K-factor (% vehicles during the design hour, normally = max. hour)

1.b Calculate the design hourly flow (Qj) = AADT x K) and enter the result in its box.

1.c Enter the traffic composition in % (based on veh/h) in Column (9)in the Table.

1.d Calculate the number of vehicles of each category as QD x % of each vehicle type and enter the results in Columns (3), (5) and (7),if necessary assuming a 50:50 directional split.

l.e Follow the procedures described in 2.b-e below.

ALTERNATIVE 2: Directional classified traffic flow counts/estimates are available for the design hour.

Enter the following input data in the Table in Form IR-2:

2.a Design hourly traffic flow values (Q) in veh/hour for each vehicletype in Columns (3), (5) and (7). Note that motorcycle flow isentered into a separate box.

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2.b Enter speed-based Ivu-values in Column (2) chosen from the left side ofthe IvuTable in Form IR-Z and capacity-based Ivu from the right side ofthe Ivu-table in Column (10).

Calculate the following parameters:

2.c Traffic flow values Q,, (Ivu/h speed-based) to be entered in Columns (4), (6) and (8), and Q (lvu/h capacity-based) to be entered in Columns (11), (12) and (13). These values are obtained throughmultiplying the flow in veh/h in Columns (3), (5) and (7) with the corresponding lvu value in Column (2) and Column (10) respectively. Motorcycle flow is not converted to Ivu at this stage.

2.d Directional split (SP) is calculated as the total flow (veh/h) in Direction1 in Column (3) divided by the total flow in Direction 1+2 (veh/h) from Column (7), excluding motorcycles. Enter the result in its box in Column (7).

2.e Motorcycle ratio (MC-ratio = QMC/Qc) is calculated by multiplying the MC flow in veh/h in Columns (3), (5) and (7) with a Ivu value of 0.25for general terrain segements, and 0.15 for specific grades to beentered in Column (10). Enter the results in Columns (11) - (13)respectively. The MC-ratio is then obtained by dividing the MC flowlvu/h in Columns (11) - (13) with the capacity-based total flow (lvu/h)of the other vehicle types higher up in the same Columns.

2.f Light vehicle unit (P) factors: P(speed) is obtained by dividing the total in Column (8) by the total in Column (7) (excluding motorcycles) andP(capacity) is obtained by dividing the total in Column (13) (excluding motorcycles) by the total in Column (7) (excluding motorcycles).

c) Traffic flow and composition for specific grades

ONLY ONE ALTERNATIVE: Hourly classified traffic flowcounts/estimates must be available for the analysis of specific grades.

Enter the following input data into the traffic flow table in Form IR-2:

- Enter lvu values into Column (2):

The Ivu value for Light vehicles (LV) is always 1.0, the lvu value forLarge Buses (LB) is always 1.5.

The Ivu values for heavy vehicles depend on the length and steepnessof the grade and are obtained from Table A-3:1. The values in the tableapply to Large Trucks (LT) and Medium Heavy Vehicles (MHV).

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Lvu values for Large Trucks (LT)

Lvu values for Medium Heavy Vehicles MHV

Gradient (%) Gradient (%)Length(km)

3 4 5 6 > 7 3 4 5 6 > 70.5 2.5 3.5 5.0 6.0 6.5 1.7 2.3 3.3 4.0 4.30.75 2.5 4.0 5.5 6.5 7.0 1.7 2.7 3.7 4.3 4.71.0 3.0 4.5 6.0 6.5 7.0 2.0 3.0 4.0 4.3 4.71.5 3.0 4.5 6.0 6.5 6.5 2.0 3.0 4.0 4.3 4.32.0 3.0 4.5 6.0 6.0 6.0 2.0 3.0 4.0 4.0 4.03.0 3.0 4.5 6.0 6.0 6.0 2.0 3.0 4.0 4.0 4.04.0 3.0 4.5 6.0 6.0 6.0 2.0 3.0 4.0 4.0 4.0

>5.0 3.0 4.5 6.0 6.0 6.0 2.0 3.0 4.0 4.0 4.0

Table A-3:1 Speed-based Ivu-values for Large Trucks (LT) and Medium Heavy vehicles (MHV) for specific grades, both directions(uphill and downhill).

- Enter traffic flow values (Q veh/h) for each vehicle type in Columns(3), (5) and (7). Observe that direction 1 is always uphill, direction 2 always downhill.

Calculate the following parameters in the same way as for general terrain:

- Traffic flow values (Qv Ivu/h) for direction I (uphill) to be entered inColumn (4) and for direction 2 (downhill) to be entered in Column (6).These values are obtained by multiplying the flow in veh/h in Columns(3) and (5) respectively with the speed-based Ivu values in Column(2).

- Add Column (4) and (6) and enter the result in Column (8).

- Directional split (SP) is calculated in the same way as above for general terrain.

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STEP A-4: SIDE FRICTION

Determine the Side Friction Class as follows:

If detailed side friction event data are available, follow steps 1-3 below, if not go directly to step 4.:

1. Enter observations (or estimates if the analysis is for a future year) regarding the frequency of side friction events along both sides of the studied segment into Column (17) in Form IR-2:

- Number of pedestrians passing along or crossing the road segment per hour per 200 m.

- Number of stopping vehicles and parking manoeuvres per hour per 200 m.

- Number of motor vehicle entries and exits to/from roadside properties and side roads per hour per 200 m.

- Flow of slow-moving vehicles (bicycles, tricycles, horsecarts, oxcarts, etc) per hour.

2. Multiply the event frequency in Column (17) with the relative weight of that event type in Column (16) and enter the result (weighted frequency of events) in Column (18).

3. Calculate the' sum of the number of weighted events including all eventtypes and enter the result in the bottom row in Column (18).

4. Determine the side friction class from Table A-4:1 based on the results from step 3. above.

If detailed side friction event data are not available, examine the descriptions of'typical conditions' from Table A-4:1 and select the one which appears best to reflectconditions on the road segment under analysis. Encircle the appropriate side friction class in the table at the bottom of Form IR-2.

Determination of side friction class:

Weighted frequency of events (both sides of road) Typical conditions Side friction class

< 50 Rural, agriculture or undeveloped; no activities

Very low VL

50- 149 Rural, some roadside buildings &activities

Low L

150 - 249 Village, residential activities Medium M250 - 350 Village, some market activities High H

> 350 Almost urban, market/businessactivities

Very high VH

Table A-4:1 Side friction classes

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STEP B : ANALYSIS OF FREE-LOW SPEED

Start at Step B-1 if the studied segment is a general terrain segment. If the segment is a specific grade, go directly to Step B-6.

Use Form IR-3 for the analysis to determine the actual free-flow speed, with the input data from Step A (Forms IR-1 and IR-2).

FV = FV0 + FFVW + FFVE + FFVRC

where:FV = Free-flow speed for actual conditions (km/h)FV0 = Base free-flow speed for pre-determined standard (ideal) conditions

(km/h)FFVW = Adjustment factor for effective carriageway width (km/h)FFVSF = Adjustment factor for side friction conditions (km/h)FFVRC = Adjustment factor for road functional class (km/h)

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STEP B-1 : BASE FREE-FLOW SPEED

Determine the base free-flow speed (FV0) for:

- light vehicles for flat terrain, and - light vehicles for actual terrain conditions

using Table B-1:1. Note that for two-lane two-way roads the base free-flowspeed.is also a function of sight distance class (from Form IR-1). If sight distanceclass is not available, assume SDC = B.

Enter these two base free-flow speed values into Columns (2) and (3) respectively of Form IR-3.

Note that only the values of free-flow speeds for light vehicles are used in thisManual. Free-flow speeds for the other vehicle classes shown in Table B-1:1 arefor reference purposes only.

Base free-flow speed FVa (km/h)Road type/ Terrain type/ (Sight distance class) Light

vehiclesLV

Largebuses

LB

Medium heavy vehicles

MHV

Largetrucks

LT

Four-lane divided- Flat terrain 78 81 65 62- Rolling terrain 69 68 56 51- Hilly terrain 62 55 46 42Four-lane undivided- Flat terrain 74 78 63 60- Rolling terrain 66 66 57 50- Hilly terrain 59 55 46 39Two-lane undivided- Flat terrain SDC: A 68 73 61 57

B 66 71 59 56 C 62 67 57 55

- Rolling terrain 61 62 52 48- Hilly terrain 55 50 42 37

Table B-1:1 Base free-flow speed FV0 for interurban roads, general terraintypes.

The free-flow speeds for six-lane roads can be taken to be the same as for four-lane roads in Table B-1:1.

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For two-lane two-way roads the effects of horizontal and vertical alignment are greater than for other road types. If detailed data on rise+fall (m/km) and horizontal curvature(rad/km) are available for the studied road segment, Table B-1:2 can be used as analternative to Table B-1:1 to obtain more precise base free-flow speeds for flat (userise+fall = 5 m/km) conditions and for actual conditions.

Base free-flow speed (LV), two-way two-lane roads

Horizontal curvature rad/km Rise + fall(m/km)

< 0.5 0.5-1 1-2 2-4 4-6 6-8 8-10

5 68 65 63 58 51 47 43

15 67 64 62 58 51 47 43

25 66 64 62 57 51 47 43

35 65 63 61 57 50 46 42

45 64 61 60 56 49 45 42

55 61 58 57 53 48 44 41

65 58 56 55 51 46 43 40

75 56 54 53 50 45 42 39

85 54 52 51 48 43 41 38

95 52 50 50 47 42 40 37

Table B-1:2 Base free-flow speeds of light vehicles as a function of road alignment.Two-way, two-lane undivided roads (2/2 UD)

Free-flow speed values for other road types as a function of horizontal and vertical alignment can be approximated by multiplying the difference between base case and actual case free-flow speeds for road type 2/2UD with a constant (given below) and then subtracting the result from the base case free-flow speed for the particular road type. (See Sub-section 2.4.2 for base cases for each road type).

The values for the constant are: - for 4/2 D Const = 1.3; for 4/2 UD Const = 1.2

Example:Calculate FV for 4/2 UD with rise+fall = 15 m/km and hor. curvature = 1.5 rad/km.

For base case 4/2 UD, FVo = 74 km/h; (from Table B-1:1)For base case 2/2 UD (SDC = A), FVo = 68 km/h (from Table B-1:1)For actual alignment 2/2 UD, FV = 62 km/h (from Table B-1:2). Adjustment for 4/2 UD = (68 - 62) x 1.2 = 7.2 km/hActual FV for 4/2 UD = 74- 7.2 = 66.8 km/h

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STEP B-2: FREE-FLOW SPEED ADJUSTMENT FACTOR FFVW FORCARRIAGEWAY WIDTH

Determine the adjustment factor FFVW (km/h) for carriageway width from TableB-2:1 based on the effective carriageway width (Wc) recorded on Form IR-2. Enter the result in Column (4).

Road type Effective carriagewaywidth (We)

(m)

FFVW (km/h)

Per lane3.00 -73.25 -33.50 0

Four-lane divided

3.75 2Per lane

3.00 -73.25 -33.50 0

Four-lane undivided

3.75 2Total

4.5 -135 -96 -37 08 29 410 511 6

Two-lane undivided

Table B-2:1 Adjustment factor FFVW for the influence of carriageway width onfree-flow speed of light vehicles

(Note that the values in Table B-2:1 were derived for flat terrain. If the studied road is not flat, an appropriate conversion is performed in Step B-5 below for all speed adjustment factors at the same time).

For roads with more than four lanes (multi-lane), the values in Table B-2:1 for 4-laneroads (divided or undivided, as appropriate) can be used as they stand.

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STEP B-3: FREE-FLOW SPEED ADJUSTMENT FACTOR FFVSF FORSIDE FRICTION

Determine the adjustment factor FFVSF (km/h) for side friction as a function of shoulder width from Table B-3:1 based on actual effective shoulder width andlevel of side friction from Form IR-2. Enter the result in Column (5) of Form IR-3.

Adjustment factor for side frictionand shoulder width (km/h) ---------------------------------------------Effective average shoulder widthWs (m)

Road type Side frictionclass (SFC)

<1.0 m 1-2 m >2mFour-lane divided Very low 0 0 04/2 D Low -3 -2 -1

Medium -6 - 4 -2High -8 -6 -3Very high -14 -11 - 4

Four-lane undivided Very low 0 0 04/2 UD Low -3 -2 -1

Medium -6 - 4 -2High -8 -6 -3Very high -14 -11 -4

Two-lane undivided Very low 0 0 02/2 UD Low -3 -2 -1

Medium -6 -5 -2High -10 -7 -3Very high -16 -12 -5

Table B-3:1 Adjustment factor FFVSF for the influence of side friction and shoulder width on the free-flow speed of light vehicles.

(Note that the values in Table B-3:1 were derived for Cat terrain. If the studied road is not flat, an appropriate conversion is performed in Step B-5 below for all speed adjustment factors at the same time).

Free-flow speed adjustment factors for roads with six lanes can be estimated by multiplying the FFVSF factors for four-lane roads given in Table B-3:1 by the factor 0.8. That is:

FFV6,SF = 0.8 x FF 4,SF

where:FFV6,SF = adjustment factor for six-lane roads ((km/h)

FFV6,SF = adjustment factor for four-lane roads (km/h)

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STEP B-4: FREE-FLOW SPEED ADJUSTMENT FACTOR FFVRc FOR ROAD FUNCTIONAL CLASS AND LAND USE

Determine the adjustment factor FFVRc (km/h) for road functional class and landuse (see Form IR-1) and enter the result in Form IR-3, Column (6).

Adjustment factor FFVRC (km/h)

Roadside development (%)

Road type

0 25 50 75 100Four-lane divided Arterial 0 -1 -2 -3 - 4

Collector -1 -2 -3 - 4 -5 Local -2 -3 - 4 -5 -6

Four-lane undivided Arterial 0 -1 -2 -3 - 4 Collector -3 - 4 -5 -6 -7 Local - 4 -5 -6 -7 -8

Two-lane undivided Arterial 0 -1 -2 -3 - 4Collector - 4 -5 -6 -7 -5

Local -7 -8 -9 -10 -11

Adjustment factor FFVRC for the influence of road functional class and land use on the free-flow speed of light vehicles.

(Note that the values in Table B-4:1 were derived for flat terrain. If the studied road is not .flat, an appropriate conversion is performed in Step B-5 below for all speed adjustment factors at the same time).

For roads with more than four lanes (multi-lane), FFVRC may be taken to be the same as for four-lane roads in Table B-4:1.

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STEP B-5: DETERMINATION OF FREE-FLOW SPEED FOR ACTUAL CONDITIONS

a) Calculate the sum of thefree-Flow speed adjustment factors in Columns (4), (5)and (6) of Form IR-3 (EFFV) and enter the result into Column (7):

FFV = (FFVW + FFVSF + FFVRC) whereFFVW = Adjustment factor for carriageway width (km/h)FFVSF = Adjustment factor for side friction and shoulder width

(km/h)FFVRC = Adjustment factor for road functional class and land use

(km/h)

If the actual case being analysed is a flat road segment, the resulting sumis entered directly into Column (8) ('Adjustment factor for actual terrainFFVACT') of Form IR-3.

b) For other (non-flat) terrain types, the 'adjustment factor for actual terrainFFVACT is calculated by multiplying the sum of the free-flow speedadjustment factors (EFFV) by the ratio of base free-flow speed for theactual terrain type and the base free-flow speed for flat terrain as shownbelow.

FFVACT = EFFV x FV0,ACT/ FV0,FLAT

The values of FVoAcT and FV0,FUT are obtained from Columns (3) and (2) respectively of Form IR-3. Enter the resulting EFFVACT value into Column (8),Form IR-3.

c) The actual free-flow speed for other (non-flat) terrain types is then obtained by adding the values in Columns (3) and (8) and entering theresulting value into Column (9) ('Actual free-flow speed FV'). That is:

FVACT = FV0,ACT + FFVACT

where:FVACT = Free-flow speed for light vehicles for the actual terrain.

(Column (9) ofForm IR-3).FV0,ACT. = Base free-flow speed for light vehicles for the actual terrain

(Column (3) of Form IR-3)FFVACT = Sum of adjustment factors for the actual terrain (Column (8) of

Form IR-3).

Though not used in this Manual, the free-flow speed for other vehicle types can be estimated by following the method used in the following example:

FVMHV = FVMHV,0 + FFV x FVMHV,0 /FV0

(See Table B-1:1 for FV0 of vehicles other than light vehicles)

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STEP B-6: FREE-FLOW SPEED FOR SPECIFIC GRADES

If the-segment is not a specific grade,. this Step B-6 should be omitted.

The free-flow speeds for light vehicles on undivded two-lane roads (2/2 UD) with specific grades must' be calculated for each direction (uphill andd downhill) separately. Use Form IR-4 when determining the free-flow speed for a specificgrade. Uphill = direction 1, downhill = direction 2.

1. Enter the values for the average slope and the length of the grade (fromIR-1).

2. Determine base free-flow speed for light vehicles for flat conditions:- from Table B-1:2 if horizontal curvature (rad/km) data are available,

using rise+fall = 5 m / km;- from Table B-1:1 if horizontal curvature data are not available. If

Sight distance class data are also not available, assume SDC=B.

and enter the results in Column (3) in separate rows for direction 1 and 2.

3. Determine the base uphill and downhill free-flow speeds FV0,UH andFV0,DH separately from Table B-6:1 below. The speeds FV0,UH and FV0,DHare a function of the gradient and length of the grade. Enter the results in Column (4) in the rows for both directions.

Direction 1, Uphill Gradient % Direction 2, Downhill Gradient %Lengthkm 3 4 5 6 7 3 4 5 6 70.5 68.0 65.7 62.6 59.5 55.2 68.0 68.0 68.0 65.7 62.61.0 67.7 64.3 60.3 56.0 51.4 68.0 68.0 67.7 64.3 60.32.0 67.6 63.4 58.9 54.3 49.5 68.0 68.0 67.6 63.4 58.93.0 67.5 63.1 58.5 53.8 48.9 68.0 68.0 67.5 63.1 58.54.0 67.4 62.9 58.2 53.4 48.5 68.0 68.0 67.4 62.9 58.25.0 67.4 62.8 58.0 53.2 48.5 68.0 68.0 67.4 62.8 58.0

Table B-6:1 Base uphill free-flow speed FV0,UH and downhill free-flow speed FVouH for light vehicles in specific grades, 2/2 UD roads

4. Calculate the actual free-flow speed for light vehicles in the uphill anddownhill directions separately, using adjustment factors described in StepsB-2 to B-4, and enter the results in Form lR-4 Columns (5) to (7), usingthe rows for each direction.

The adjustment factors for actual conditions in Columns (5) to (7) are then summed separately for the uphill and downhill directions to give

FFVAC,DH and FFVACT,DH and entered into the appropriate rows of Column (8).

The sums of the adjustment factors in Column (8) ( FFVACT,DH andFFVACT,DH) are applicable only to flat terrain and must now be further

adjusted for actual terrain,

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separately for uphill and downhill directions. This is done bymultiplying the sum of the adjustment factors in Column (8) by the ratio ofbase free-flow speed for actual terrain in Column (4) and the base free-flowspeed for flat terrain in Column (3). This is the same process as described inStep B-5 above. The resulting values are entered into the uphill and downhill rows of Column (9).

The final values for the free-flow uphill and downhill speeds (Column (4) + Column (9)) are entered into Column (10).

5. To calculate the combined speed consider the flow for light vehicles in the two directions.

QLV1 is the light vehicle flow in direction I (uphill) QLV2 is the light vehicle flow in direction 2 (downhill) QLV = QLV1 + QLV2 is the light vehicle flow for both directions

The average free-flow speed for both directions FV is now calculated as:

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STEP C: ANALYSIS OF CAPACITY

If the segment is a specific grade, go directly to Step C-6 and use Form IR-4 rather than Form I R-3.

Use the input data from Forms IRA and IR-2 to determine the capacity, usingForm IR-3.

C = C0 x FCW x FCSP x FCMC x FCSF (Ivu/h)

where:C = Capacity (Ivu/h)Co = Base capacity for pre-determined (ideal) conditions (Ivu/h) FCW = Adjustment factor for carriageway width FCSP = Adjustment factor for directional split FCMC = Adjustment factor for motorcycle trafficFC.SF = Adjustment factor for side friction

STEP C-1: BASE CAPACITY

Determine the base capacity (C0) from Table C-1:1 and enter the value into Form IR-3,Column (11). (Observe that the effect of terrain type on capacity is also accounted for by the use of different lvu-values as described in Step A-3).

Road type/ Terrain type

Base capacity (Ivu/h) Comment

Four-lane divided Per lane- Flat terrain 1900- Rolling terrain 1850- Hilly terrain 1800Four-lane undivided Per lane- Flat terrain 1700- Rolling terrain 1650- Hilly terrain 1600Two-lane undivided Total in both directions- Flat terrain 3100- Rolling terrain 3000- Hilly terrain 2900

Table C-1:1 Base capacity C0 for interurban roads

Base capacities for roads with more than four lanes (multi-lane) can be estimated using the capacites per lane given in Table C-1:1, even if the lanes are of non-standard width (correction for width is made in Step C-2 below).

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STEP C-2 : CAPACITY ADJUSTMENT FACTOR FCW FOR CARRIAGEWAY WIDTH

Determine the adjustment factor FCW for carriageway width from Table C-2:1 based on the actual effective carriageway width (WC) (see Form IR-2) and enter the result in Form IR-3, Column (12).

Road type Effective carriageway width(We)(m)

FCW

Per lane

3.0 0.913.25 0.963.50 1.00

Four-lane dividedAverage effectiveshoulder width

3.75 1.03Per lane

3.00 0.913.25 0.96

3.50 1.00

Four-lane undivided

3.75 1.03Total both directions

4.5 0.695 0.816 0.91

7 1.008 1.08

9 1.15

10 1.21

Two-lane undivided

11 1.27

Table C-2:1 Adjustment factor FCW for the influence of carriageway width oncapacity.

Capacity adjustment factors for roads with more than four lanes (multi-lane) can be estimated using the figures per lane given for four-lane roads in Table C-2:1.

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STEP. C-3; CAPACITY ADJUSTMENT FACTORS FOR TRAFFICCONDITIONS

a). Capacity adjustment factor for directional split

For undivided roads only, determine the capacity adjustment factor for directional split (FCSP) from Table C-3:1 below based on the input data for traffic conditions from Form IR-2, Column (7), and enter the value into Column (13) in Form JR-3.

Table C-3:1 gives the directional split adjustment factors for two-lane two-way (2/2)and four-lane two-way (4/2) undivided roads.

Directional split SP %-% 50-50 55-45 60-40 65-35 70-30

FCSP. Undivided roads 1.00 0.97 0.94 0.91 0.88

Table C-3:1 Directional split capacity adjustment factor (FCC,)

For divided roads, the capacity adjustment factor (or directional split is not applicable and a value of 1.0 should be entered into Column (13).

b) Capacity adjustment factor for motorcycle traffic

Determine the capacity adjustment factor (FCc) for motorcycle ratio in the traffic flowfrom the formula below based on the motorcycle ratio as calculated in Form IR-2 Column(13) and enter the value into Column (14) in Form IR-3.

FCMC = 1 - QMC / QC

where QMC = Motorcycle flow (Ivu/h) = 0.25 x Motorcycle flow (MC/h) QC = Sum of flow for all other motor vehicle types (LV, MHV, LB,

LT) expressed in capacity-based lvu/h.

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STEP C-4: CAPACITY ADJUSTMENT FACTOR FCSF FOR SIDE FRICTION

Determine the capacity adjustment factor FCSF for side friction conditions from Table C-4:1 based on effective shoulder width WS from Form IR-1, and side friction lass(SEC) from Form IR-2, and enter the result in Form IR-3 Column (15).

Adjustment factor for side friction FC5F

Shoulder width WSRoad type Side friction

class< 0.5 1.0 1.5 > 2.0

4/2 D VL 0.98 1.0 1.02 1.04

L 0.92 0.95 0.99 1.02

M 0.86 0.90 0.96 0.99

H 0.80 0.85 0.93 0.96

VH 0.75 0.80 0.90 0.94

VL 0.96 0.98 1.0 1.03

2/2 UD L 0.90 0.92 0.95 0.99

4/2 UD M 0.83 0.86 0.90 0.96

H 0.76 0.80 0.85 0.93

VH 0.70 0.74 0.80 .0.90

Table C-4:1 Adjustment factor FCSF for the influence of side friction on capacity

Capacity adjustment factors for 6-lane can be estimated using the FCSF values forfour-lane roads given in Table C-4:1, modified as illustrated below:

Adjustment factor for six-lane roads FC 6,E

FC6.SF = 1 - 0.8 x (1 – FC4, SF)

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STEP C-5: DETERMINATION OF CAPACITY FOR ACTUAL CONDITIONS

Determine the capacity of the road segment for actual conditions with the help ofthe data filled into Form IR-3 Columns (11)-(15) and enter the result in Column(16):

C = C0 x FCw x FCSP x FCMC x FCSF (Ivu/h)

where:

C = Capacity (Ivu/h)C0 = Base capacity for pre-determined (ideal) conditions (Ivu/h)FCW = Adjustment factors for carriageway widthFCSP = Adjustment factor for directional splitFCMC = Adjustment factor for motorcycle flowFCSF = Adjustment factor for side friction

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STEP C-6: CAPACITY FOR SPECIFIC GRADES

The capacity for a specific grade is calculated in essentially the same way as forgeneral terrain segments above, but with different base capacity and in somecases with different adjustment factors. Form IR-4 should be used for the analysisof specific grades.

C = C0 x FCW x FCSP x FCMC x FCSF, (Ivu/h)

The two-way base capacity (C0) is determined from Table C-6:1. Enter the valueinto Form IR-4, Column (12).

Length of grade/ Slope of grade

Base capacitylvu/h

Length < 0.5 km/all slopes 3000

Length < 0.8 km/Slope < 4.5% 3000

All other cases 2900

Table C-6:1 Base capacity C0 for specific grades on two-lane roads

The adjustment factor for carriageway width FCW is the same as in Table C-2:1above for two-lane undivided roads. Enter the value in Form IR-4, Column (13).

The adjustment factor for directional split FCSP is determined from Table C-6:2below. It is based upon the percentage of traffic in the uphill direction (direction 1). Enter the value into Form IR-4, Column (14).

Percent traffic uphill (dir. 1) FCSR

70 0.7865 0.8360 0.8855 0.9450 1.0045 1.0340 1.0635 1.0930 1.12

Table C-6:2 Directional split adjustment factor for specific grades on two-lane roads

The adjustment factor for the ratio of motorcycles is calculated according to the formulabelow, based on the input data from Form IR-2 for traffic conditions.

FCMC = 1 - QMC/ Qc

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where QMC = Motorcycle Flow (Ivu/h)= 0.15 x Motorcycle flow (MC/h)

QC = Sum of flow for all other motor vehicle types (LV, MHV,LB, LT) expressed in capacity-based Ivu/h.

Enter the value into Column (14) in Form IR-4.

The adjustment factor for side friction FCsF is the same as in Table C-4:1 above. Enterthe value into Form IR-4, Column (15).

Determine the capacity of a specific grade for actual conditions from the values in FormIR-4 Columns (11)-(15) and enter the result into Column (16).

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STEP D : LEVEL OF PERFORMANCE If the segment is a specific grade, go directly to Step D-4.

Use the input conditions determined in Step A-3 (Form IR-2) and the free flowspeed and capacity determined in Steps B and C (Form IR-3) to determine degree of saturation, speed and travel time, and ratio of bunching. Use Form IR-3 for level of performance analysis.

STEP D-1 : DEGREE OF SATURATION

SPEED-BASED DEGREE OF SATURATION

1. Read the resulting total traffic flow value Q„ (lvu /h, speed-based, excl.MC) from Form IR-2 Columns (8) for undivided roads, and Columns (4) and (6) for each separate direction of divided roads and enter the valueinto Form IR-3 Column (21). (Note: when analysing a climbing lane on a specific grade (see D-4 below) put the traffic flow for the uphill direction only into Column (21)).

2. Using the actual capacity from Column (16) of Form IR-3, calculate the ratio between QV and C to determine the degree of saturation (DSV,speed-based) and enter the value into Column (22).

DSV = QV/C (speed-based lvu)

CAPACITY-BASED DEGREE OF SATURATION

3. Read the resulting traffic flow value QC (Ivu/h, capacity-based, excl.MC) from Form IR-2 Column (13) for undivided road and Columns(11)-(12) for divided roads and enter the value into Form IR-3 Column(31).

4. Using the actual capacity from Column (16) of Form IR-3, calculate the ratio between QC and C to determine the degree of saturation (DSC,capacity-based) and enter the value into Column (32):

DSC = QC/C (capacity-based lvu)

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STEP D-2: SPEED AND TRAVEL TIME

l Determine the speed at actual traffic, side friction and geometric conditions as follows.

- Select value for degree of saturation DS as follows:

Use DSV, (speed-based) from Column (22) if DV < 0.85Use DSC (capacity-based) from Column (32) if DSV > 0.85otherwise:Use 0.85.

- Use Figure D-2:1 (two-lane undivided roads) or Figure D-2:2 (four-lane roads or one-way roads) as follows:

a) Enter with the chosen DS value on the horizontal (x) axle at thebottom of the figure.

b) Make a line parallel with the vertical (y) axle from this pointsuntil it intersects with the level for actual free-flow speed fromForm IR-3 Column (9).

c) Make a horizontal line parallel with the (x) until it reaches the vertical (y) axle at the left side of the figure and read a value for actual light vehicle speed for the analysed conditions.

d) Enter this value into Column (23) in Form IR-3.

2 Enter the length of the segment L (km) in Column (24) (from Form IR-l).

3 Calculate the average travel time for light vehicles in hours for the studied case,and enter the result in Column (25):

Average travel time TT = L/ V (hour)

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Figure D-2:1 Speed as a function of Q/C for 2/2 UD roads

Figure D-2:2 Speed as a function of Q/C for four-lane roads

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STEP D-3: DEGREE OF BUNCHING (PLATOONING)

For roads of four or more lanes, bunching is not calculated.

Determine the degree of bunching (DB) on two-lane, two-way undivided roads based on thedegree of saturation DSc in Column (32) using Figure D-3:1 below, and enter the valueinto Column (33) in Form 1R-3. Bunching is defined in this Manual as the ratio between theflow of motor vehicles (excluding motorcycles) with a time headway of less than or.equal to 5 seconds to the nearest vehicle in front travelling in the same direction, andthe total flow (veh/h) in the studied direction(s).

DB = (vehicles with headway <5 sec)/Q (in vehicles excluding motorcycles and unmotorised)

Figure D-3:1 Degree of bunching on 2-lane 2-way roads as a function of degree of saturation based on capacity (QC/C)

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STEP D-4: SPEED AND TRAVEL TIME FOR SPECIFIC GRADES

For a specific grade it is in general more useful just to consider the uphill directionregarding speed. Use Form IR-4 for this calculation:

1. Calculate the degree of saturation (DS„) in the same way as above in StepD=1. Use Columns (21) and (22) in Form IR-4.

2. The Uphill speed at capacity (VUHC km/h) is determined depending on the gradient (%) and length of the grade (L, km): Table D-4:1 below gives the uphill speed for light vehicles at capacity. Enter the value into Form IR-4,Column (23).

'Uphill speed at capacity L, kmGradient

0.5 1 1.5 2 2,5 3 38.0 35.0 33.5 32.5 32.04 31.0 28.5 27.0 26.0 25.55 26.5 24.0 22.5 22.0 21.56 22.5 20.5 19.5 18.5 18.07 19.5 17.5 16.5. 16.0 15.5

Table D-4:1 Uphill speed at capacity VUHC for light vehicles on specific grades.

3. Calculate the difference in speed between the uphill free flow speedFVUH and the uphill speed at capacity VUHC The uphill free flow speed has been calculated in Step B-6 above and has already been entered into Form IR-4 Column (10), direction 1. Enter the speed difference (FVUH - VUHC) in Column (24) of Form IR-4.

4. Calculate the actual uphill speed for light vehicles VUH (km/h) can now be calculated as

VUH = FVUH – DSV x (FVUH - VUHC)

Enter the result into Column (25).

5. The average travel time is calculated in the same way as in Step D-2 above. Use Columns (26) and (27) in Form IR-4.

6. If the overall speed for both directions is desired, then Figure D-2:1 abovein Step D-2 can be used with reasonable accuracy. In this case use the table for "Actual speed for light vehicles" in Form lR-3 for thecalculations.

If the grade has a climbing lane, consider the uphill direction as two lanes of a four lane undivided road in hilly terrain. Perform the calculations with Forms IR-1, IR-2 and IR-3 and use the data for four-lane undivided roads. In Form IR-3enter directly the uphill free-flow speed into Column (9) (from Column (10) ofForm IR-2), calculated as described in Step B-6, without using Columns (2) - (8).Steps C and D are then performed as a four lane undivided road, bearing the following in mind:

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- traffic flow data (including MC ratio) are needed for the uphill direction onlyin Form IR-2;

- the directional split .adjustment factor for specific grades from Table C-6:2should be used, though it is not now a two-lane road;

- use Ivu values for hilly terrain;

STEP D-5: EVALUATION OF LEVEL OF PERFORMANCE

This Manual has been primarily designed to estimate consequences regarding capacityand level of performance of a set of given conditions regarding geometric road design, traffic and environment. Since the outcome usually cannot be predicted beforehand, it is quite likely that it will be necessary to revise some of the conditions which are within the engineer's control, particularly geometric conditions, in order to get a desired level ofperformance regarding capacity and speed etc.

The quickest way to evaluate the results is to look at the degree of saturation (DS) for thestudied case, and to compare it with the annual traffic growth and the desired functional "life" of the road segment in question. If the obtained DS values are too high, the user might want to revise his assumptions regarding road cross section etc andmake a new set of calculations. This will then require a new set of forms with a newassigned case number. Note that for divided roads, the evaluation must be carriedout by direction first in order to arrive at an overall evaluation.

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4. CALCULATION PROCEDURE FOR PLANNING ANALYSIS

For planning, the design of the road and the traffic and environmental data would be known in general, but not in detail, and forecast traffic flow would normally be given in AADT, rather than as peak hour flow. Consequently, certain assumptions about geometric design, traffic and environment have to be made. The relationship between the flow in the peakhour or design flow (QD) and AADT must also be assumed. This relationship is normally expressed as an AADT-factor K as follows

K = QD/AADT

Planning analyses are normally carried out for both directions combined,even if it is anticipated that the road will have a median. (There is no difficulty with this as a 50:50 directional split is assumed for planning).

4.1 BASIC ASSUMPTIONS FOR DIFFERENT ROAD TYPES

4.1.1 Two-lane two-way roads (2(2 UD)

The assumptions used for planning of two-lane two-way roads are as follows:

Road function: Arterial (national or provincial)

Cross section: 7 m carriageway, 1.5 m effective shoulder width on bothsides

Sight distance: 50% of the segment has sight distance more or equal to 300m (SDC=B)

Terrain type: Flat, rolling or hilly (see Section 1.3)

Environment: Rural area with 25% developed roadside land use

Side friction: Low (see Section 1.3)

Traffic composition: LV: 63%; MHV 25%: LB: 8%; LT 4% (excluding MC)MC: 10% (of total flow including MC)

K-factor: Design hourly volume = 0.11xAADT (K = 0.11)

Directional split: 50/50

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4.1.2. Four-lane two-way roads (4/2)

The assumptions used for planning of four-lane two-way roads are as follows;


Carriageway: 2x2 lanes, lane width 3.50 m

Shoulders: Undivided road (4/2 UD):Average 1.5 m effective shoulder width on both sidesin flat and rolling terrain, 1 m in hilly terrain.Divided road (4/2 D):Average 1.0 m effective shoulder width (inner =; 0.25 m and outer = 1.75 m)/2 per direction in flat and rolling terrain, 0.75 to in hilly terrain (inner = 0.25 mand outer = 1.25 m)/2.

Sight distance: 75% of the segment has sight distance more or equalto 300 m (SDC = A)


Environment: Village area with 50% developed roadside land use.

Side friction: Medium (see Section 1.3)

Traffic composition: LV: 63%; MHV 25%: LB: 8%; LT 4% (excluding MC)MC: 10% (of total flow including MC)

K-factor: Design hourly volume = 0.l1xAADT (K = 0.11)


4.1.3 Six-lane two-way roads (6/2 D)

The assumptions used for planning of six-lane two-way roads are asfollows:



Median: Yes (6/2 D)

Shoulders: Average 1.0 m effective shoulder width (inner = 0.25 m and outer = 1.75 m)/2 per direction in flat and rolling terrain, 0.75 m in hilly terrain (inner = 0.25 m and outer = 1.25 m)/2.

Sight distance: 75% of the segment has sight distance more or equalto 300 m (SDC = A )

6 - 61



Environment: Village area with 50% developed roadside land use.

Side friction: Medium (see Section 1.3)

Traffic composition: LV: 63%; MHV 25%: LB: 8%; LT+TC 4% (excluding MC) MC: 10% (of total flow including MC)

K-factor: Design hourly volume 0.11xAADT (K = 0.11)

Directional split: 50 / 50

6 - 62


4.2 ANALYSIS OF ROAD PERFORMANCE

On the basis of the assumptions recorded in Section 4.1 above, the procedures proposed for operation and design analysis have been applied to produce Table 4.2:1 below, which relates AADT or QD to the level ofroad performance expressed as:

- Free flow speed (equal to speed at AADT = 0) - Degree of saturation (Speed-based: DSV = QV/C) (Capacity-based: DSC = QC /C)- Speed (km/h) at different flow levels and degree of saturation Q/C- Degree of bunching (only for road type 2/2 UD)

INTERURBAN HIGHWAYS

Table 4-2:1 Level of performance as a function of road type and AADT

6 - 63


Table 4-2:1 can be used in the following main ways :

a) To estimate the level of performance for different road types at givenAADT or design hour (QD) levels. Linear interpolation can be carriedout for flow values which fall between given values in the top of thetable.

b) To estimate the level of traffic flow in AADT which can beaccommodated by different road types whitin a permissible level ofperformance regarding degree of saturation, speed and degree of bunching.

If the base assumptions regarding K-factor and traffic composition are notvalid for the studied case, Table 4-2:1 can be entered using design hourly flows (QD) as follows:


.1 Calculate QD = AADT x K (veh/h)

.2 Calculate P-factors for conversion from veh/h to speed-based lvu/h (for speed-based Ivu values see Form IR-2) as follows:

Actual conditions: Pact = (LVact% x lvuLV + MHVact % x lvu MHV + LBact % x lvuLB +

LTact% x lvuLT)/100

Assumed standard conditions (see Section 4.1) Pass = (LVass% x lvuLV + MHVass% x lvuMHV + LBass% x lvuLB + LTass%

x 1vuLT)/100

.3 Calculate adjusted Design hourly flow (QDadj) in veh/h:

QDadj = QAADT x K x Pact/Pass (veh/h)

.4 Use the calculated value of QDadj instead of the actual QD when entering Table 4.2:1

No worksheet is needed to perform the above mentioned evaluations.However, if conditions are known to be significantly different from theassumed conditions given in Section 4.1 above, then appropriate value(s)should be used and an operational/design analysis performed instead asdescribed in Section 3. This would first require conversion of AADT topeak hour, using an AADT factor (default: K = 0.11). Examples of cases where an operational analysis would be needed are:

- if the traffic is expected to be quite different from the assumed values, e.g. K-value, traffic composition, directional split. Form IR-2will then have to be applied to calculate design hourly flow, andForm IR-3 should be used for the calculation of the differentmeasures of performance.

- if the carriageway width differs very much for the planned segmentto be analysed;

6 - 64


- if the horizontal and vertical alignment differs very much from the assumed, general terrain types.

- if the land use and side friction differ by more than one class fromthe assumptions made.

6 - 65


5. WORKED EXAMPLES

5.1 CONVERSION INTO RADIANS/KM

Suppose a road segment of length 3.0 km has a horizontal alignment as shown in thesketch shown in Figure 5-1:1 below:

Figure 5-1:1 Example of horizontal alignment

The horizontal curvature (rad/km) is calculated as follows:

6 - 66


5.2 EXAMPLE 1: OPERATIONAL ANALYSIS OF A TWO-LANE TWO-WAY ROAD (2/2 LTD)

CONDITIONS

CASE A:1994

Geometry : 6.0 m effective carriageway width 1.0 m effective shoulderon both sides (level with road) 50 % of the segment with sight distance > 300 m (SDC = B) Road functional class:collector.

Terrain : Flat terrain

Traffic : Classified flow count March 1994 both directions:

Vehicle type- Light vehicles: - Medium heavy vehicles: - Large buses:- Large trucks + truck comb.:- Motorcycles:

Veh/design hour 1,16845513959159

Directional split of 55 - 45

Land use : Rural agricultural area with 25% developed roadside land use.

Side friction : No measurements of frequency of side friction events are available, but no activities which could result in side frictionevents have been noted.

QUESTION 1:

Calculate the following values for the actual conditions and time (March 1994) forCase A:1994:

- Actual free-flow speed - Actual capacity- Degree of saturation (speed- and capacity-based)- Actual speed- Degree of bunching

6 - 67


QUESTION 2:

Assume an annual traffic increase of 7%, equally spread over all vehicle types.

Predict the following parameters for the year 2000 (after six years) (other conditions remain unchanged):

CASE A:2000- Degree of saturation, speed-based and capacity-based- Actual speed- Degree of bunching

QUESTION 3:

Using the traffic data for the year 2000 (from Question 2 above) predict the effect on capacity, degree of saturation and degree of bunching of the following alternative measures (other conditions remain unchanged):

CASE B:2000 Widening of the carriageway to 10 m (2/2 UD)CASE C:2000 Widening of the carriageway to 14 m (4/2UD).

In both cases the new shoulder has an effective width of 1.0m on each side.

SOLUTIONS:

The data and calculations are set out in the Forms below.

1. Case A: 1994:

- Actual free-flow speed = 58 km/h- Actual capacity = 2,628 lvu/h - Degree of saturation, speed-based = 0.83 - Degree of saturation, capacity-based = 0.78 - Actual speed = 37 km/h- Degree of bunching = 0.86

2. Case A:2000:

- Traffic at year 2000: LV = 1,168 x (1 + 0.07)6 = 1,753MHV = 455 x (1 + 0.07)6 = 683LB = 139 x (1 + 0.07)6 = 209LT+TC = 59 x (1 + 0.07)6 = 89MC = 159 x (1 + 0.07)6 = 239

- Degree of saturation, speed-based = 1.24 - Degree of saturation, capacity-based = 1.17

6 - 68


- Actual speed = Cannot be calculated for over-saturated conditions - Degree of bunching = Cannot be calculated for over-saturated conditions

Note that the calculated degrees of saturation indicate that traffic demand for the design hour considerably exceeds capacity. In practice this indicates jamconditions.

3. Case B:2000:

- Actual free-flow speed = 66 km/h- Actual capacity = 3,494 lvu/h - Degree of saturation DSv = 0.94 ( > 0.85)- Degree of saturation DSc = 0.88 ( > 0.85, so use 0.88)- Actual speed = 41 km/h- Degree of bunching = 0.89

Case C:2000:

- Actual free-flow speed = 70 km/h- Actual capacity = 6,335 Ivu /h - Degree of saturation DSv = 0.52- Degree of saturation DSc = 0.48- Actual speed = 61 km/h- Degree of bunching is valid only for 2/2 UD.

6 - 69

Rev 25/8 94 /KLB HCM: INTERURBAN ROADS & MOTORWAYS

Form IR - 1

Date: AUGUST 261994 Handled by: DK

Province: WEST JAVA Cheked by: NWM

Link no : 22003 Segment code: KM 84-94

Segment between SERANG and TANGGERANG

Admin. Road class: NATIONAL Road type: 2/2 UD

Length (km): 10 Functional class COLLECTOR

INTERURBAN ROADS & MOTORWAYSFORM IR-1 : INPUT DATA

GENERAL DATAROAD GEOMETRY

Time period: MARCH 1994 Case number: A : 1994

Horizontal alignment

Horizontal curvarture (rad/km): NA Side A Side B MeanSight distance > 300 m (%) 50 SDC B

RoadsideDevelopment (%) 25 25 25

Vertikal alignment

Terrain type : (encircle) Flat, Rolling , Hilly Slope in % (spesific grade) : NA

Rise + fall (m/km) : NA Length in km (specific grade) : NA

Cross section

Side A Side B Total Mean

Effective Carriageway Witdh (Wc , m): 3 3 6

Average effective shoulder witdh (Ws , m) 1 1 3 1

Road surface conditions

CARRIAGEWAY : Type of pavement : Flexible (asphalt), Concrete, Grafel

Pavement conditions : Good , Fair , Bad

IRI : NA

SHOULDERS : Side A Side B

Shoulder conditionsinner outer inner Outer

Surface type: (Flexible = F, Stone =,Earth = E) NA S NA S

Drop relative carriageway (cm) : NA O NA O

Usability: (Traffic=T, Parking=P, Emergency stop=E) NA P NA P

Traffic control conditions :

Speed limit (km/h) : NA Other : NA

Max gross weight (tones) : NA

6 - 70


Form IR - 1













Vertikal alignment



Cross section







IRI : NA









6 - 71


Form IR - 1













Vertikal alignment



Cross section







IRI : NA









6 - 72


Form IR - 2 ITERURBAN ROADS & MOTORWAYS Date : AUGUST 26,1994 Handled by: DK

FROM IR-2 : INPUT DATA Link no : 22003 Checked by: NWM

TRAFFIC FLOW Segment code : KM 84 – 94

SIDE FRICTION Case number : A : 1994

Light vehicle units Ivu

Ivu (speed) Ivu (capacity) General terrain type/Road type

LV MHV LB LT LV MHV LB LT

Flat terrain/Divided road Flat terrain/Undivided road Rolling terrain/All road typesHilly terrain/All road types

1.01.01.01.0

1.51.52.03.5

1.01.21.31.5

3.22.74.05.5

1.01.01.01.0

1.21.21.31.5

1.51.51.72.0

2.02.02.53.0

Traffic flow and composition

Alt : 1 AADT AND TRAFFIC COMPOSITION DATA ARE AVAILABLE

AADT (veh/day) = k-faktor (design hour/AADT) = Design hourly flow =

Alt : 2 HOURLY CLASSIFIED TRAFFIC FLOW DATA ARE AVAILABLE

Traffic flow Qv (speed-based) Traffic flow Qc (capacity-based)

Dir. 1 Dir. 2 Dir. 1+2 Dir.1 Dir.2 Dir.1+2Vehicletype Ivu(speed –

based) Veh/h Ivu/h Veh/h Ivu/h Veh/h Ivu/h %Ivu (capacity- based) Ivu/h Ivu/h Ivu/h

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

LVMHVLBLT

1.01.51.22.7

1,16845513959

1,168683167160

1.01.21.52.0

1.168546209118

Total 1,821 2,178 2.041

MC 159 0,25 40

Directional split SP = Totals (3)(7) x 100 (%) 55 MC ratio = Qmc/Qc 0.02

Pv (speed-based) = Totals (8)(7) 1,196 Pc (capacity-based) = totals (13)(7) 1.121

Side friction Class

If detailed data are available , use the first table to determine weighted frequency of events,And then go to the second table. If not, use the second table only.

1. Determination of frequency of events

Side friction type of events symbol Weightingfactor

FrequencyOf events

Weightedfrequency

(14) (15) (16) (17) (18)PedestrianParking, stopping vehicles Entry + exit vehicles Slow-moving vehicles

PEDPSVEEVSMV

0.60.81.00.4

NA / h,200m NA / h,200m NA / h,200m NA / h

Calculation of weightedFrequency of events per Hour and 200 mOf the studied road segment, Both sides of the road.

Total :

2. Determination of side friction class

Weighted frequency of events Typical conditions Side friction class< 50

50 – 149 150 – 249 250 – 349

> 350

Rural, agriculture or undeveloped, no activities Rural, some roadside buildings & activitiesVillage, residential activitiesVillage, some market activities Almost urban, market/business activities

Very lowLowMediumHighVery high

VLLMH

VH

6 - 73





SIDE FRICTION Case number : A : 1994





1.01.01.01.0

1.51.52.03.5

1.01.21.31.5

3.22.74.05.5

1.01.01.01.0

1.21.21.31.5

1.51.51.72.0

2.02.02.53.0








(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

LVMHVLBLT

1.01.51.22.7

1,75368320989

1,7531,025251241

1.01.21.52.0

1,753820314178

Total 2,734 3,270 3,065

MC 239 0,25 60

Directional split SP = Totals (3)(7) x 100 (%) 55 MC ratio = Qmc/Qc 0,02

Pv (speed-based) = Totals (8)(7) 1,196 Pc (capacity-based) = totals (13)(7) 1,121

Side friction Class




FrequencyOf events

Weightedfrequency


PEDPSVEEVSMV

0.60.81.00.4



Total :



50 – 149 150 – 249 250 – 349

> 350



VLLMH

VH

6 - 74


Form IR - 3INTERURBAN ROADS & MOTORWAYS Date : AUGUST 26, 1994 Handled by : DKFORM IR-3 : ANALYSIS Link no : 22003 Cheked by : NWM

SPEED, CAPACITY Segment code : KM 84 -94

BUNCHING Case number : A : 1994 A : 2000 B : 2000 C : 2000

Free flow speed for light vehicles FV = FVo + FFVw + FFVrc ( km/h )

Free flow speed adjustment factor (km/h) Base free Flow speed FV0Tab B-1:1 or 2

Km/hCaseNo.

Flatterrain

Actualterrain

CarrieagewayWitdhFCw

Table B-2:1

Side friction FFVsf

Table B-3:1

Road function ClassFFVrc

Table B-4:1

TotalFFV

(4)+(5)+(6)

Adj. factor For actual

terrainFFVact

(7) x (3) / (2)km / h

Actual free Flow speed

FVact

(3) + (8)km/h

(1) (2) (3) (4) (5) (6) (7) (8) (9)A :1994 A :2000 B :2000 C :2000

66666674

66666674

- 3 - 3 50

0000

- 5 - 5 - 5 - 4

- 8 - 8 0

- 4

- 8 - 8 0

- 4

58586670

Capacity C = Co x FCw x FCsp x FCmc x FCsf

Free flow speed adjustment factor (km/h)

CaseNo.

Base CapacityCo

Table C-1:1Ivu/h


Table C-2:1

Directional split FCw

Table C-3:1

Motorcycle ratio FCmc =

1 – Qmc/Qc

Side friction FCsf

Table C-4:1

ActualCapacityC Ivu/h

(11) x (12) x (13) x (14) x(15)

(10) (11) (12) (13) (14) (15) (16)A :1994 A :2000 B :2000 C :2000

3,1003,1003,1006,800

0,910,911,211,00

0,970,970,970,97

0,980,980,980,98

0,980,980,980,98

2,6282,6283,4946,335

Actual speed for light vehicles

CaseNo.

Traffic flowQv

Speed-basedIvu/h

Degree ofsaturation

DSv = Qv/C (21)/ (16)

ActualSpeed VIv

Fig D-2:1 or 2 Km/h

RoadSegmentLength L

km

Travel time TT

(24) / (23)h

(20) (21) (22) (23) (24) (25)A :1994 A :2000 B :2000 C :2000

2,1783,2703,2703,270

0,831,240,940,52

37NA4161

10101010

0,270NA

0,2440,164

Degree of bunching

CaseNo.

Traffic flowQc

Speed-basedIvu/h

Degree ofsaturation

DSv = Qv/C (31)/ (16)

Degree ofBunching

DBFigure D-3:1

(30) (31) (32) (33)

A :1994 A :2000 B :2000 C :2000

2,0413,0653,0653,065

0,781,170,880,48

0,86NA

0,89NA

6 - 75


5.3 EXAMPLE2: PLANNING ANALYSIS

CONDITIONS

CASE A:

Terrain : Rolling terrain

Traffic : AADT 15,000 year 1995

Assumed traffic composition (excl MC):Vehicle type %- Light vehicles: 60- Medium heavy vehicles: 25- Large buses: 10- Large trucks + truck comb.: 5

Directional split of 55 - 45

Annual traffic increase: 8%

Land use : Rural area passing some small villages with limited roadsideactivities..

Questions:

1. Which road type is required to maintain an average speed of at least 50km/h during the design hour?

2. In which year will this road type obtain a degree of saturation (DSV) during the design hour which is equal to 0.85?

3. In which year will upgrading be required, in order to maintain an averagespeed of at least 50 km/h and, when upgrading, what standard, road type(s) should be used?

6 -76


Solutions:

No worksheet is needed to answer these questions: Table 4-2:1 should be used directly.

1. Traffic composition, directional split and side friction are similar to the basic assumptions for planning analyses, so the options are (from Table 4-2:1):

Road type Terrain AADT(veh /day) Qv/C Speed

km/h

2/2 UD Rolling 15,000 0.82 384/2 UD Rolling 15,000 0.37 544/2 D Rolling 15,000 0.35 576/2 D Rolling 15,000 0.23 59

The conclusion is that at least a 4/2 UD road type is needed, which will give a speed of 54 km/h.

2. From Table 4.2:1 for 4/2 UD in rolling terrain:

QV/C = 0.85; AADT = 35,000 veh/day; Speed = 42 km/h

35,000 = 15,000 (1 + 0.08)" n = 11 years

A degree of saturation equal to 0.85 will occur in the year 2006.

3. From Table 4.2:1 the speed for the 4/2UD road in rolling terrain will dropto 52 km/h when the AADT reaches 20,000 and to 49 km/h when it reaches 25,000.

20,000 = 15,000 (1 + 0.08)" n = 4 years 25,000 = 15,000 (1 + 0.08)" n = 7 years

So to maintain at least the 50 km/h speed, upgrading will be needed when AADT reaches nearly 25,000 in about 6 years (2001).

For upgrading to a standard design, two better road types are available: 4/2D and 6/2D. Which is likely to be the most appropriate design?

For 4/2 D : AADT = 25,000 veh/day; speed = 52 km/h AADT = 30,000veh/day; speed = 49 km/h

25,000 = 15,000 (1+0.08)" n = 7 years30,000 = 15,000 (1+0.08)" n = 9 years

So upgrading to 4/2D would probably maintain the speed at 50 km/h until AADT reaches just under 30,000 in, say, 8 years (2003). As upgrading to4/2D would there-

6 -77


fore only maintain the 50 km/h speed for a further two years before a 6/2D road is needed, it would seem more sensible to go directly to the 6/2Ddesign.

For 6/2 D : AADT = 40,000 veh/day; Speed= 51 km/hAADT = 45,000 veh/day; Speed = 49 km/h

40,000 = 15,000 (1 + 0.08)" n = 13 years45,000 = 15,000 (1 + 0.08)" n = 14 years

The 6/2D design will therefore maintain the speed of the road at 50 km/h until the AADT has reached between 40,000 and 45,000 in the year 2008 or 2009.

Conclusion: the road must be upgraded in about the year 2001. It would seem best to upgrade it directly to 6/2D, which would maintain a speed of 50 km/h until about 2008.

6 -78


5.4 EXAMPLE-3: OPERATIONAL ANALYSIS OF A SPECIFIC GRADE

An interurban national two-lane road in hilly terrain has a grade of average slope7%, 3 km long. It carries a volume of 750 veh/h. Other relevant characteristicsinclude:

Road characteristics: 6.5 m carriageway width with 1 m shoulders. The developed roadside land use is on average 25%. The road is an arterial.

Traffic characteristics: 450 veh/h in uphill direction and 300 veh/h in downhill direction, 60% LV, 10% LB, 25% MHV and 5% LT. The total MC-flow is 60 MC/h equally distributed between the two directions.

Side friction characteristics can be considered as low. There are someroadside activities.

Questions:

1. What uphill speed can be expected for light vehicles (VUH)?

2. What is the capacity of the grade?

3. As a measure to improve the road, an extra climbing lane of width 3.5m isplanned to be added to the upgrade. The shoulders are unchanged and are still I m in width. What uphill speed for LV can now be expected?

6 -79


Solutions:

See Forms below.

1. VLV = 24.8 km/h

2. C = 2,238 Ivu / h

3. VLV = 43 km/h is the uphill speed after the climbing lane is provided.

6 -80

Rev 25/8 94/KLB HCM: INTERURBAN ROADS & MOTORWAYS

Form IR - 1 Date: AUGUST 261994 Handled by: DK


Link no : 22003 Segment code: KM 28 – 31

Segment between BANDUNG and SUBANG

Admin. Road class: PROVINCIAL Road type: 2/2 UD

Length (km): 3 Functional class ARTERIAL



Time period: JUNE 1994 Case number: A : 1994 SG


Horizontal curvarture (rad/km): NA Side A Side B MeanSight distance > 300 m (%) NA SDC B


Vertikal alignment

Terrain type : (encircle) Flat, Rolling , Hilly Slope in % (spesific grade) : 7

Rise + fall (m/km) : 70 Length in km (specific grade) : 3

Cross section


Effective Carriageway Witdh (Wc , m): 3,25 3,25 6,5





IRI : NASHOULDERS :

Side A Side B Shoulder conditions

inner outer inner OuterSurface type: (Flexible = F, Stone =,Earth = E) NA S NA S






6 - 81





SIDE FRICTION Case number : A : 1994 SG





1.01.01.01.0

1.51.52.03.5

1.01.21.31.5

3.22.74.05.5

1.01.01.01.0

1.21.21.31.5

1.51.51.72.0

2.02.02.53.0








(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

LVMHVLBLT

1.04.01.56.0

2701124523

27044868

138

180753015

1803004590

4501877538

450748113228

Total 450 924 300 615 750 1.539

MC 30 30 60 0,15 9


Pv (speed-based) = Totals (8)(7) 2.052 Pc (capacity-based) = totals (13)(7)

Side friction Class




FrequencyOf events

Weightedfrequency


PEDPSVEEVSMV

0.60.81.00.4



Total :



50 – 149 150 – 249 250 – 349

> 350



VLLMH

VH

6 - 82


Form IR - 4INTERURBAN ROADS & MOTORWAYS Date : AUGUST 26, 1994 Handled by : DK

FORM IR-4 : ANALYSIS Link no : 22075 Checked by : NWM

SPECIFIC GRADES Segment code : KM 28 – 31

SPEED, CAPACITY Case number : A : 1994 SG

Specific grade : Slope% : length km :

Free flow speed for light vehicles FV = FVo + FFVw + FFVsf + FFVrc (km/h)

Free flow speed adjustment factor (km/h) Base free Flow speed FVo

CaseNo.

Direction1 = Uphill 2 = Downhill

FlatTerrainTableB-1:1

ActualTerrainTableB-6:1

CarriagewayWidthFCw

Table B-2:1

Side friction FFVsf

Table B-3:1

Road functionClassFFVrc

Table B-4:1

TotalFFV

(5) + (6) + (7)

Adj. factor For actual RoadFFVact(8) x (4) / (3)km / h

Up- and downhillfree flowspeed

FVuh, FVdh (4) + (9)km / h

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)

A:1994A:1994

12

6666

48.958.5

- 1.5 - 1.5

- 2 - 2

- 1 - 1

- 4.5 - 4.5

- 3.3 - 4

45.654.6

Qlv veh/h = Qlv veh/h = Qlv = Qlv1 + Qlv2 veh/h :

Capacity C = Co x FCw x FC sp x FCmc x FCsf


CaseNo.

Base CapacityCo

Table C-6:1Ivu/h

CarriagewayWidthFCw

Table C-2:1

Side friction FFVsf

Table C-6:2

Motorcycle ratioFCmc=

1 – Qmc/Qc

Side friction FCsf

Table C-4:1

ActualCapacity

C

(12) x (13) x (14) x (15) x (16)

(11) (12) (13) (14) (15) (16) (17)

A:1994 2.900 0.96 0.88 0.993 0.92 2.238

Actual uphill speed

CaseNo.

Traffic flowQv

Ivu/h

Degree ofSaturation

DSv = Qv/C (21) / (17)

Uphill speed At capacity

VuhcTable D-4:1

Km/h

SpeedDifference

FVuh – Vuhc(10) - (23)

km/h

Actual uphill Speed

VuhFVuh-(23)x(24)

Km/h

RoadSegmentLength L

km

Uphill travelTimeTT

(26) / (25)h

(20) (21) (22) (23) (24) (25) (26) (27)

A:1994 1.539 0.69 15.5 30.1 24.8 3 0.121

180 450270

37

6 - 83


Form IR - 1 Date: AUGUST 261994 Handled by: DK


Link no : 22003 Segment code: KM 28 – 31

Segment between BANDUNG and SUBANG

Admin. Road class: PROVINCIAL Road type: 2/2 UD




Time period: JUNE 1994 Case number: A : 1994 SG


Horizontal curvarture (rad/km): NA Side A Side B MeanSight distance > 300 m (%) NA SDC B


Vertikal alignment

Terrain type : (encircle) Flat, Rolling , Hilly Slope in % (spesific grade) : 7

Rise + fall (m/km) : 70 Length in km (specific grade) : 3

Cross section


Effective Carriageway Witdh (Wc , m): 6,75 3.25 10





IRI : NASHOULDERS :


inner outer inner OuterSurface type: (Flexible = F, Stone =,Earth = E) NA S NA S






6 - 84





SIDE FRICTION Case number : B : 1994 SG





1.01.01.01.0

1.51.52.03.5

1.01.21.31.5

3.22.74.05.5

1.01.01.01.0

1.21.21.31.5

1.51.51.72.0

2.02.02.53.0








(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

LVMHVLBLT

1.03.51.55.5

2.701124523

27039268

127

Total 450 857 750

MC 30 60 0.15 9


Pv (speed-based) = Totals (8)(7) 1,196 Pc (capacity-based) = totals (13)(7)

Side friction Class




FrequencyOf events

Weightedfrequency


PEDPSVEEVSMV

0.60.81.00.4



Total :



50 – 149 150 – 249 250 – 349

> 350



VLLMH

VH

6 - 85


Form IR - 3INTERURBAN ROADS & MOTORWAYS Date : AUGUST 26, 1994 Handled by : DKFORM IR-3 : ANALYSIS Link no : 22075 Cheked by : NWM

SPEED, CAPACITY Segment code : KM 28 -31

BUNCHING Case number : B : 1994 SG



Km/hCaseNo.

Flatterrain

Actualterrain


Table B-2:1

Side friction FFVsf

Table B-3:1


Table B-4:1

TotalFFV

(4)+(5)+(6)


terrainFFVact

(7) x (3) / (2)km / h


FVact

(3) + (8)km/h

(1) (2) (3) (4) (5) (6) (7) (8) (9)

B:1994 45.6



CaseNo.

Base CapacityCo

Table C-1:1Ivu/h


Table C-2:1


Table C-3:1


1 – Qmc/Qc

Side friction FCsf

Table C-4:1


(11) x (12) x (13) x (14) x(15)

(10) (11) (12) (13) (14) (15) (16)

B:1994 3.200 0.98 0.94 0.993 0.92 2.693


CaseNo.

Traffic flowQv

Speed-basedIvu/h

Degree ofsaturation

DSv = Qv/C (21)/ (16)

ActualSpeed VIv

Fig D-2:1 or 2 Km/h

RoadSegmentLength L

km

Travel time TT

(24) / (23)h

(20) (21) (22) (23) (24) (25)

B:1994 857 0.32 43 3 0.07

Degree of bunching

CaseNo.

Traffic flowQc

Speed-basedIvu/h

Degree ofsaturation

DSv = Qv/C (31)/ (16)

Degree ofBunching

DBFigure D-3:1

(30) (31) (32) (33)

6 - 86


6. REFERENCES

Rl. TRB Highway Capacity Manual.Transportation Research Board, SpecialReport 209;Washington D.C. USA 1985.

R2. May, A.D. Traffic Flow Fundamentals.Prentice-Hall, Inc; 1990.

R3. Easa, S.M. Generalized Procedure for EstimatingMay, A.D. Single- and Two-Regime Traffic-Flow

Models.Transportation Research Records 772;Washington D.C. USA 1980.

R4. Hoban, C.J. Evaluating Traffic Capacity and Improvements to Road Geometry.World Bank Technical Paper Number 74; Washington D.C. USA 1987.

R5. OECD Traffic Capacity of Major Routes.Road Transport Research; 1983.

R6. Brannolte,U. Highway Capacity and Level of Service. (editor) Proceedings of International Symposium on

Highway Capacity, Karlsruhe; RotterdamNetherlands 1991.

R7. McShane, W.R. Traffic Engineering. Roess, R.P. Prentice-Hall, Inc; 1990.

R8. Black, J.A., Land Use along Arterial Roads: Friction and Impact.

Westerman, H.L. The University of New South Wales; 1988. Blinkhorn, L. McKittrick, J.

R9. McLean, J.R. Two-Lane Highway Traffic Operations.Theory and Practice.Gordon and Breach Science Publisher;_1989.

R10. TRB Highway Capacity Manual (RevisedChapter 7: Multilane Rural and SuburbanHighways).Transportation Research Board; Washington D.C. 1992.

R1 1. NAASRA Guide to Traffic Engineering Practice.National Association of Australian State Road Authorities; 1988.

6 - 87


R12. Directorate General Standard Specification for Geometric Designof Highways of Interurban Roads. Ministry of Public

Works; 1990

R13 Ministry of Public Works Keputusan Menteri Pekerjaan UmumNomor 552/KPTS/1991 tentang PenetapanRuas-Ruas Jalan sebagai Jalan NasionalIndonesia. Jakarta; 1991.

R14 Government of Indonesia Undang-Undang Republik Indonesia No.13 Tahun 1980 tentang Jalan.

R15 Directorate General of Peraturan Pemerintah Republik Indonesia Highways Nomor 26 Tahun 1985 tentang Jalan.

Ministry of Public Works; 1985.

R16 Government of Indonesia Undang-Undang Republik Indonesia No. 14 Tahun 1992 tentang Lalu-Lintas & Angkutan Jalan.

R17 Akcelik, R Proceeding of the Second InternationalSymposium on Highway Capacity. TRBCommittee A3A10, Sydney August 1994.

6 - 88

Rev 25/8 94/KLB HCM: INTERURBAN ROADS & MOTORWAYS Appendix 6.1

Form IR - 1 Date: Handled by:

Province: Cheked by:

Link no : Segment code:

Segment between and

Admin. Road class: Road type:

Length (km): Functional class



Time period: Case number: Horizontal alignment

Horizontal curvarture (rad/km): Side A Side B MeanSight distance > 300 m (%) SDC

RoadsideDevelopment (%)

Vertikal alignment

Terrain type : (encircle) Flat, Rolling , Hilly Slope in % (spesific grade) :

Rise + fall (m/km) : Length in km (specific grade) :

Cross section


Effective Carriageway Witdh (Wc , m):

Average effective shoulder witdh (Ws , m)




IRI : SHOULDERS :


inner outer inner OuterSurface type: (Flexible = F, Stone =,Earth = E)

Drop relative carriageway (cm) :

Usability: (Traffic=T, Parking=P, Emergency stop=E)


Speed limit (km/h) : Other :

Max gross weight (tones) :

6 - 89


Form IR - 2 ITERURBAN ROADS & MOTORWAYS Date : Handled by:

FROM IR-2 : INPUT DATA Link no : Checked by:

TRAFFIC FLOW Segment code :

SIDE FRICTION Case number :





1.01.01.01.0

1.51.52.03.5

1.01.21.31.5

3.22.74.05.5

1.01.01.01.0

1.21.21.31.5

1.51.51.72.0

2.02.02.53.0








(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

LVMHVLBLT

Total

MC

Directional split SP = Totals (3)(7) x 100 (%) MC ratio = Qmc/Qc

Pv (speed-based) = Totals (8)(7) Pc (capacity-based) = totals (13)/ (7)

Side friction Class




FrequencyOf events

Weightedfrequency


PEDPSVEEVSMV

0.60.81.00.4



Total :



50 – 149 150 – 249 250 – 349

> 350



VLLMH

VH

6 - 90


Form IR - 3INTERURBAN ROADS & MOTORWAYS Date : Handled by : FORM IR-3 : ANALYSIS Link no : Cheked by :

SPEED, CAPACITY Segment code :

BUNCHING Case number :



Km/hCaseNo.

Flatterrain

Actualterrain


Table B-2:1

Side friction FFVsf

Table B-3:1


Table B-4:1

TotalFFV

(4)+(5)+(6)


terrainFFVact

(7) x (3) / (2)km / h


FVact

(3) + (8)km/h

(1) (2) (3) (4) (5) (6) (7) (8) (9)



CaseNo.

Base CapacityCo

Table C-1:1Ivu/h


Table C-2:1


Table C-3:1


1 – Qmc/Qc

Side friction FCsf

Table C-4:1


(11) x (12) x (13) x (14) x(15)

(10) (11) (12) (13) (14) (15) (16)


CaseNo.

Traffic flowQv

Speed-basedIvu/h

Degree ofsaturation

DSv = Qv/C (21)/ (16)

ActualSpeed VIv

Fig D-2:1 or 2 Km/h

RoadSegmentLength L

km

Travel time TT

(24) / (23)h

(20) (21) (22) (23) (24) (25)

Degree of bunching

CaseNo.

Traffic flowQc

Speed-basedIvu/h

Degree ofsaturation

DSv = Qv/C (31)/ (16)

Degree ofBunching

DBFigure D-3:1

(30) (31) (32) (33)

6 - 91


Form IR - 4INTERURBAN ROADS & MOTORWAYS Date : Handled by :

FORM IR-4 : ANALYSIS Link no : Checked by :

SPECIFIC GRADES Segment code :

SPEED, CAPACITY Case number :

Specific grade : Slope% : length km :

Free flow speed for light vehicles FV = FVo + FFVw + FFVsf + FFVrc (km/h)

Free flow speed adjustment factor (km/h) Base free Flow speed FVo

CaseNo.

Direction1 = Uphill 2 = Downhill

FlatTerrainTableB-1:1

ActualTerrainTableB-6:1

CarriagewayWidthFCw

Table B-2:1

Side friction FFVsf

Table B-3:1

Road functionClassFFVrc

Table B-4:1

TotalFFV

(5) + (6) + (7)

Adj. factor For actual RoadFFVact(8) x (4) / (3)km / h

Up- and downhillfree flowspeed

FVuh, FVdh (4) + (9)km / h

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)

Qlv veh/h = Qlv veh/h = Qlv = Qlv1 + Qlv2 veh/h :

Capacity C = Co x FCw x FC sp x FCmc x FCsf


CaseNo.

Base CapacityCo

Table C-6:1Ivu/h

CarriagewayWidthFCw

Table C-2:1

Side friction FFVsf

Table C-6:2

Motorcycle ratioFCmc=

1 – Qmc/Qc

Side friction FCsf

Table C-4:1

ActualCapacity

C

(12) x (13) x (14) x (15) x (16)

(11) (12) (13) (14) (15) (16) (17)

Actual uphill speed

CaseNo.

Traffic flowQv

Ivu/h

Degree ofSaturation

DSv = Qv/C (21) / (17)

Uphill speed At capacity

VuhcTable D-4:1

Km/h

SpeedDifference

FVuh – Vuhc(10) - (23)

km/h

Actual uphill Speed

VuhFVuh-(23)x(24)

Km/h

RoadSegmentLength L

km

Uphill travelTimeTT

(26) / (25)h

(20) (21) (22) (23) (24) (25) (26) (27)

6 - 92

Chapter 7

MOTORWAYS

CHAPTER 7

MOTORWAYS

TABLE OF CONTENTS

1. INTRODUCTION ..................................................................................... 7 – 3

1.1 SCOPE AND OBJECTIVES ........................................................................... 7 – 31.2 MOTORWAY CHARACTERISTICS ......................................................... 7 – 41.3 DEFINITIONS AND TERMINOLOGY ..................................................... 7 – 51.4 LOCAL VERIFICATION ............................................................................ 7 – 5

2. METHODOLOGY .....................................................................................7 – 8

2.1 GENERAL APPROACH .............................................................................7 – 82.2 VARIABLES .................................................................................................7 – 92.3 BASIC RELATIONSHIPS ............................................................................7 – 102.4 GEOMETRIC CHARACTERISTICS ............................................................7 – 172.5 OVERVIEW OF THE CALCULATION PROCEDURE ............................7 – 18

3. CALCULATION PROCEDURE FOR OPERATIONAL ANALYSIS AND DESIGN .............................................................................................7 – 20

STEP A: INPUT DATA .............................................................................7 – 21 A-1: General data ......................................................................7 – 21A-2: Geometric conditions ........................................................7 – 23

A-3: Traffic conditions .............................................................7 – 23STEP B: ANALYSIS OF FREE-FLOW SPEED ...........................................7 – 28

B-1: Base free-flow speed ........................................................7 – 29B-2: Speed adjustment factor for carriageway and shoulder

width ................................................................................7 – 30B-3: Determination of free-flow speed for actual

conditions …………………………………………………7 – 31B-4: Free-flow speed for specific grades ...................................7 – 32

STEP C: ANALYSIS OF CAPACITY ......................................................7 – 34C-1: Base capacity .....................................................................7 – 35C-2: Capacity adjustment factor for carriageway width ... ..........7 – 36C-3: Capacity adjustment factor for directional split ...................7 – 37C-4: Determination of capacity for actual conditions ..................7 – 37C-5: Capacity for specific grades ...............................................7 – 38

STEP D: LEVEL OF PERFORMANCE ......................................................7 – 39D-1: Degree of saturation ..........................................................7 – 39D-2: Speed and travel time ……………………………………. 7 – 39

7 - 1

D-3: Degree of bunching (platooning)……………………. 7 – 42D-4: Speed and travel time for specific grades…………. 7 – 43D-5: Evaluation of level of performance…………………. 7 – 44

4. CALCULATION PROCEDURE FOR PLANNING ANALYSIS ........... 7 – 45

4.1 BASIC ASSUMPTIONS FOR DIFFERENT MOTORWAY TYPES ……… 7 – 454.2 ANALYSIS OF MOTORWAY PERFORMANCE ………………………… 7 – 48

5. WORKED EXAMPLES ……………………………………………………… 7 – 50

5.1 EXAMPLE-1: OPERATIONAL ANALYSIS OF A TWO-LANE TWO-WAY UNDIVIDED MOTORWAY (MW 2/2 UD) ..... 7 – 50

5.2 EXAMPLE-2: PLANNING ANALYSIS ……………………………. 7 – 55

7. REFERENCES …………………………………………………………………. 7 – 57

7 - 2

HCM: MOTORWAYS

1. INTRODUCTION

1.1 SCOPE AND OBJECTIVES

1.1.1. Definition and facility types

This Chapter presents procedures for the calculation of free-flow speed, capacity, speed and degree of bunching on motorways designed for interurban conditions. Motorways are defined as roads for through trafficwith complete access control, whether or not they are divided roads. InIndonesia, this definition is currently synonymous with 'toll road'.

If the motorway segment to be analysed is designed for urban conditions, then go to Chapter 5 on Urban Roads.

The interurban motorway types presented in this Chapter are of two types:

- Two-lane two-way undivided (MW 2/2 UD)

- Four-lane two-way divided (MW 4/2 D).

The Manual can also be used to analyse divided motorway designs with more than four lanes.

1.1.2. Application

The geometric characteristics of the road types used in this Chapterare defined in Section 2.4.2 below. For each of the defined roadtypes, the calculation procedures can be applied for:

- operational analysis, design and planning of motorways in flat, rollingor hilly terrain;

- operational analysis of specific grades on two-lane, two- way undivided motorways.

1.1.3. Motorway segments

The procedures in the Manual are applied to calculations for individualsegments of a road. A motorway segment is defined as a length of motorway:

- between and unaffected by interchanges with on- and off-ramps, and

- having similar geometric design and traffic flow characteristics alongits length.

Points where road characteristics change significantly automaticallybecome the boundary of a segment even if there is no nearby interchange. The motorway characteristics of

7 - 3

HCM: MOTORWAYS

importance in this respect are discussed below.

Interurban motorway segments can generally be expected to be considerablylonger than urban and suburban motorway segments because geometric and other characteristics generally change less frequently andinterchanges are much less closely spaced. They can be tens of kilometresin length. However it is important that segment boundaries are madewherever characteristics change significantly, even if the resulting segmentsare very much shorter than this.

Segment boundaries should be set where terrain type changes, even though other characteristics of geometry and traffic remain the same. It ishowever not necessary to be concerned about minor changes in geometry,particularly if they are intermittent.

1.2 MOTORWAYCHARACTERISTICS

The main characteristics of a motorway which will affect its capacity and its performance when loaded with traffic are identified below. Any point on a particular motorway where there is a significant change in geometric design and traffic flow characteristics becomes the boundary of amotorway segment as described in Section 1.1.3. above.

1.2.1. Geometry

- Width of carriageway: capacity increases with carriageway width.

- Shoulder characteristics: performance at a given flow, improves with increasing shoulder width. Drivers on the motorways in the Jabotabek area have the habit of using the paved shoulder as an extra lane when the normal traffic lanes become congested. This factor has not been taken account of in the Manual, since it should be strongly discouragedfor safety reasons.

- Presence or absence of median (i.e. divided or undivided motorway):well-designed medians increase capacity. There may however be otherreasons why a median is not preferred, e.g. lack of space, cost etc..

- Vertical curvature: the more hilly the terrain through which the motorway passes, the lower will be the capacity and the performance at a given flow.

- Horizontal curvature: undivided motorways with long straights, fewbends and few hill-brows allow for longer sight distances and so foreasier overtaking, giving a higher capacity.

1.2.2. Flow, composition and directional split

- Directional split of traffic on undivided motorways: capacity is highestwhen the directional split is 50 - 50: that is to say when the flows are equal in both directions.

7 - 4

HCM: MOTORWAYS

- Traffic composition: if flow and capacity are measured in veh/h,traffic composition will affect capacity. However, by measuring flow in light vehicle units (Ivu), as in this Manual, this effect hasbeen accounted for.

1.2.3. Traffic control

Controls on maximum and minimum speed, heavy vehicle movements,incident management of broken down vehicles etc. will affect the capacity of the motorway.

1.2.4. Driver and vehicle population

Driver behaviour and vehicle population (the age, power and condition of vehicles within each vehicle class, as distinct from vehicle composition)differ between different parts ofIndonesia. Older vehicles of a" given type, orless urgent driver behaviour could result in lower capacity and performance.As no direct measures of these effects are possible, these characteristics maybe incorporated into the calculations locally as discussed in Section 1.4 below.

1.3 DEFINITIONS AND TERMINOLOGY

See Chapter 6 Section 1.3 for a list of terminology.

1.4 LOCALVERIFICATION

A number of factors specific to particular areas (such as driver and vehicle population) can affect the parameters given in this Manual. If they have theresources and appropriate expertise, users of the Manual are stronglyrecommended to measure key parameters (such as free-flow speed and capacity) on a small number of representative sites within their study area,and to apply local adjustment factors on free-flow speed and capacity if theobtained values differ significantly from the values obtained by using this Manual.

7 - 5

HCM: MOTORWAYS

Four-lane motorway with provision for future widening to six lane

Four-lane motorway with narrow median and guard rail

7 - 6

HCM: MOTORWAYS

Two-lane undivided motorway

Undivided motorway with extra climbing lane for slower vehicles

7 - 7

HCM: MOTORWAYS

2. METHODOLOGY

2.1 GENERAL APPROACH

The calculation procedures given in the Manual are in some cases similar, at least in general form, to those in the 1985 U.S. Highway Capacity Manual (US HCM) and its 1992 revisions. This is intentional, as users of this Manual may already befamiliar with the US HCM procedures. Due to the limited amount ofmotorway data collection sites in Indonesia, some input has also been obtained from the US HCM, particularly regarding the impact on capacityof lane width.

2.1.1. Type of calculations

The procedures given in this Chapter allow the calculation of the followingtraffic characteristics for a given motorway segment:

- free flow speed (i.e. speed at flow = 0);- capacity; - degree of saturation (flow/capacity);- speed at actual flow conditions;- degree of bunching at actual flow conditions (only for two-lane

motorways);- traffic flow which can be accommodated by the given motorway

segment while maintaining a specified level of performance (speed or bunching).

Calculation methods for ramps and weaving sections on motorways are not included in this Manual, but are discussed in principle in Section 2.2.3 below. See also the methods for single weaving sections in the HCM-1 Manual,Chapter 4.

2.1.2. Levels of analysis

Procedures are given in this Chapter to enable analysis to be carried out at one of two levels:

- Operational analysis and design: The determination of theperformance of a motorway segment under existing or projected traffic demand. The capacity can also be calculated, as can themaximum flow which can be carried while still maintaining a specifiedlevel of performance. The motorway width or number of lanes neededto carry a given flow of traffic while maintaining an acceptableperformance level can also be calculated for design purposes. The effects on capacity and performance of anumber of other design features, e.g. provision of a median or modifications to shoulder width, can also be assessed. This is the most detailed level of analysis.

- Planning: As for design, the objective is to estimate the number of lanes needed for a projected motorway, but the information on flow is likely to be given only as estimated AADT. The details ofgeometry and other inputs can either be assumed or be based onrecommended default values.

7 - 8

HCM: MOTORWAYS

The methods used in operational and design analysis, and the methods used inplanning analyses are related and differ mainly in the level of detail in theinputs and outputs. Steps in planning analyses are very much simpler in mostcases.

The procedures given in this Chapter also allow operational analyis to be carried out on one of two different types of motorway segments:

- General terrain segments: In this case the segment is allocated to a terrain type which reflects the general horizontal and vertical curvature conditions of the segment - flat, rolling or hilly.

- Specific grades: A continuous steep section of road can act as a capacity'bottleneck' in both the uphill and downhill directions and can have performance effects which are not fully accounted for by subsuming thesteep section within a general terrain type. For this reason this Manualalso allows for the operational analysis of specific grades. The specificgrade procedures given in the Manual essentially only apply to two-lane two-way roads as gradient problems are usually worst on thisroad type. The procedures allow the effects of the grade to be calculatedas a basis for determination of remedial actions, such as wideningor providing a crawler lane.

2.1.3. Period of analysis

The capacity analysis of motorways is performed for peak one-hour periods, and flows and mean speeds are expressed for this period. To use a full day (AADT) analysis period would be too coarse for operational analysis anddesign. Throughout the Manual, flow is expressed as an hourly rate (Ivu/h),unless otherwise stated.

For planning, in which AADT is normally given, tables are provided to convert flows directly from AADT to performance measures and vice versa, under certain assumed conditions.

2.1.4. Divided and undivided roads

For undivided roads, including undivided motorways, all analyses(other than the analysis of specific grades) are carried out on both directionsof travel combined, using one set of analysis forms. For divided roads, analyses are performed separately for each direction of travel, using adifferent set of analysis forms for each direction, as though each direction were a separate one-way road.

2.2 VARIABLES

2.2.1. Traffic flow and composition

Throughout the Manual the traffic flow values (Q) reflect trafficcomposition, by expressing flow in light vehicle units (Ivu). All traffic flowvalues (per direction and total) are

7 - 9

HCM: MOTORWAYS

converted to light vehicle units (Ivu) using empirically derived lvu values for the following types of vehicles (see definitions in Chapter 6, Section 1.3):

- Light vehicles (including passenger cars, minibuses, pickup trucks and jeeps).

- Medium heavy vehicles (including two-axle trucks and smallbuses).

- Large buses.- Large trucks (including three-axle trucks and truck combinations).

Two sets of Ivu values with different criteria for equivalency are used:

- Speed-based lvu values based on the relative impact on light vehicle speed of adding different types of vehicles into the traffic stream.

- Capacity-based Ivu values based on the relative impact on capacity of different vehicle types.

2.2.2. Free flow speed

Free flow speed (FV) is defined as the speed at flow level zero,corresponding to the speed a driver would choose if he/she was driving a motor vehicle which was not restrained by another motor vehicles on the motorway.

Free flow speeds have been observed by field data collection, fromwhich the relationship between free flow speed and geometric design conditions have been determined by means of regression. The free flow speed for light vehicles has been chosen as base criteria for the performanceof a motorway segment at flow = 0. Free flow speeds for medium heavyvehicles, large buses and large trucks are also given for reference (definitionssee Section 1.3):

The equation for determination of free flow speed has the following general shape:

FV = FVo + FFVW

where:FV = Free flow speed for light vehicles for the actual conditions. FV0 = Base free flow speed for light vehicles for the studied motorway

and terrain type, ideal (pre-defined, see Section 2.4 below). FFVW = Adjustment factor for carriageway and shoulder width (km/h).

2.2.3. Capacity

MOTORWAY CAPACITY

Capacity is defined as the maximum flow pass a point on the motorway that can be sustained on an hourly basis under prevailing conditions. For undivided motorways capacity is expressed as a two-wayflow (both directions combined), for divided motorways it is expressed ascapacity per lane.

7 - 10

HCM: MOTORWAYS

Capacity values have been observed by field data collection whenever possible. Due to the lack of sites with flows near to the capacity of the motorway segment itself (rather than the capacity of intersections along the motorway), capacity has also been estimated theoretically by assuming a mathematical relationship between density, speed and flow, see Section 2.3.1below. The capacity (C) is expressed in light vehicle units (lvu), see below.

The basic equation for determination of capacity is as follow:

C = Co x FCW x FCsr

where:C = actual capacity (Ivu/h) Co = base (ideal) capacity for predefined (ideal) conditions (Ivu/h)FCW = motorway width adjustment factor FCSP = directional split adjustment factor (only for undivided

motorways)

RAMP CAPACITY

The formula above gives the capacity CMW of a motorway segment with a given crosssection. The capacity CR of an on-ramp on the same segment can be approximated as described below:

CR = The lowest value of the following expressions:

1) The capacity of the ramp itself, calculated using the methodsin Chapter 6 as a function of the cross section and alignmentof the ramp.

2) The difference between the capacity CMW,L and the flowQMW,L in the left lane of the motorway.

CR = CMW.L - QMW,L

The capacity of the left motorway lane CMWE,L can be calculated using the methods described in Section 3C below.

The flow in the left motorway lane QMW,L normally varies with the totalflow and degree of saturation of the motorway segment. Figure 2.2.3:1 belowexemplifies field observations on the Jakarta - Cikampek Toll Road in thisrespect. For very low flows (which were not observed), almost all the traffic will probably use the left lane.

7 - 11

HCM: MOTORWAYS

Figure 2.2.3:1 Observed lane distribution in one direction of travel on a four-lane divided motorway (MW 4/2)

2.2.4. Degree of saturation

Degree of saturation, (DS) defined as the ratio of flow to capacity, is used as a key factor in the determination of the level of performance of an intersection. This is a widely used measure to indicate whether a motorwaysegment is expected to have capacity problems or not.

DS = Q/C

For analysis of the level of performance regarding speed, DSV is calculatedusing Q expressed in speed-based Ivu values (QV). For analysis of degree ofbunching (DB), DSc is calculated using flow expressed in capacity-based Ivu values (Qc).

2.2.5. Speed

The Manual uses travel speed (synonymous with journey speed) as the mainmeasure of performance of motorway segments, since it is easy to understandand to measure, and is an essential input to motorway user costs in economicanalysis. Travel speed is defined in this Manual as the space mean speed of light vehicles (LV) over the motorway segment:

7 - 12

HCM: MOTORWAYS

V = L/TT

where:V = space mean speed of LV (km / h) L = length of segment (km)TT = mean travel time of LV over the segment (h)

2.2.6 Degree of bunching

A further useful indicator of the level of performance of an undivided motorway segment is the degree of bunching that occurs, i.e. the ratio of flow of vehicles travelling in platoons to total flow. In this Manual bunchinghas been defined as occurring when one or more vehicles follow a platoonleader with a headway (front axle to front axle) of less than or equal to 5 seconds.

2.2.7 Level of performance

In the US HCM motorway performance is represented by Level of Service (LOS): a qualitative measure reflecting the drivers' perception of the quality of driving. LOS is related in turn to a quantitative proxy measure, such asdensity, per cent time delay or journey speed. The level of service concept was developed for use in the United States and the LOS definitions do not directly apply to Indonesia. It is also difficult to produce alternative definitions forIndonesia whose meanings would be clear. For this reason, speed, degree ofsaturation and degree of bunching (for undivided motorways) are used asindicators for level of performance in this Chapter.

2.3 BASIC RELATIONSHIPS

2.3.1. Speed-flow-density relationships

The general principle underlying the capacity analysis of motorway segments is that speed decreases as flow increases. The speed decrease with unit flowincrease is near constant at low and medium flows, but becomes greater as flows get closer to capacity. Near capacity a small increase in flows results in alarge decrease in speed.

Typical relationships between speed and density (calculated as Q/V) and between speed and flow are illustrated with the help of field data in Figures 2.3.1:1-4 below. A good mathematical representation of theserelationships can often be obtained using the Single regime model:

V = FVx[1 - (D/Dj)(@-l ]1/(1-m); D0/Di = [(1-m)/(@-m)] 1/(@)

where:D = Density ivu/km (calculated as Q/V)Di = Density at completely "jammed" motorwayD0 = Density at capacity@, m = Constants

7 - 13

HCM: MOTORWAYS

For two-lane undivided roads the speed-flow relationship is often close tolinear and can be represented by a simple linear model.

Data from the field surveys has been analysed to obtain typical speed flow-relationships for motorways using this technique. Flow on the horizontal axis has been replaced with degree of saturation (Q/C), and a number of curves have been traced representing different fee-flow speed levels in order to make the relationships generally applicable as exemplified in Section 3Step D.

Speeds are generally lower in Indonesia than in developed countries at a given degree of saturation (flow/capacity = Q/C).

2.3.2. Relationship between degree of saturation and degree of bunching

Degree of bunching (DB) is a variable which is more sensitive to flow thanspeed, and so provides a reasonable approximation of level of performanceon undivided motorways. The same type of mathematical modelling as described for speed above has been applied to develop generalisedrelationships between degree of saturation (DS) and degree of bunching (DB)as exemplified in Chapter 6, Section 2.3.2.

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Figure 2.3:1 Speed-density relationship for four-lane, divided motorways

Figure 2.3.1:2 Speed – flow relationship for four-lane, divided motorways

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Figure 2.3.1:3 Speed – density relationship for two-lane, undivided motorways

Figure 2.3.1:4 Speed – flow relationship for two-lane, undivided motorways

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2.4 GEOMETRIC CHARACTERISTICS

2.4.1. Terrain type

Three general terrain types recommended for use in operational as well asplannng analysis:

Terrain type Rise + fall(m/km)

Horizontal curvature (rad/km)

Flat terrain < 10 <1.0

Rolling terrain 10-30 1.0-2.5

Hilly terrain >30 > 2.5

Note: See also definitions in Chapter 6, Section 1.3.

For special studies of 2/2 UD motorways the Manual also presents freeflow speed as a general function of vertical alignment expressed as rise+fall (m/km) and of horizontal alignment expressed as curvature(rad/km).

2.4.2. Base cases for different motorway types

a) Two-lane, two-way undivided motorway (MW 2/2 UD)

This motorway type encompasses all two-way motorways with a carriageway width between 6.5 to 7.5 metres.

The base case motorway of this type is defined as follows:

- Seven metre carriageway width - Shoulders of effective width of 1.0 m on each side- No median- Directional traffic split of 50 - 50- Terrain type : flat- Sight distance class : A

b) Four-lane, two-wav divided motorway (MW 4/2 D)

This motorway type encompasses all motorways with lane widths from 3.25 to 3.75 m. The standard motorway of this type is defined asfollows:

- 2 x 7.2 metre carriageways - Shoulders of effective width of 2.0 m (inner + outer)/2 for each

carriageway

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- Median- Terrain type : flat- Sight distance class : A

c) Six-lane or eight-lane divided motorways can also be analysed using the same basic characteristics as described above.

2.5 OVERVIEW OF THE CALCULATION PROCEDURE

A flow chart of the calculation procedure for operational analysis and design purposes is presented in Figure 2.5:1 below. The different stepsare described step-by-step in detail in Section 3.

The following forms are used for the calculations:

IR-1 Input data:- General conditions- Road geometry

IR-2 Input data (cont.):- Traffic flow and composition

IR-3 Analysis for general motorway segments: - Free flow speed - Capacity - Actual speed - Degree of bunching

IR-4 Analysis for specific grades- Free flow speed- Capacity- Actual uphill speed

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CALCULATION PROCEDURE Operational analysis and design

Figure 2.5:1 Overview of the calculation procedure for operational analysis and design

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3. CALCULATION PROCEDURE FOR OPERATIONAL ANALYSIS AND DESIGN

The objectives of operational analysis for a particular motorway segment,under an existing or projected set of geometric, traffic and environmentalconditions can be:

- to determine capacity;

- to determine the degree of saturation (DS = Q/C) associated with an existing or projected traffic flow;

- to determine the speed in which the road will operate.

- to determine the traffic flow distribution and operating characteristicsof different lanes.

The main objective of design analysis is to determine the required road width to maintain a desired level of performance. This could mean carriagewaywidth or number of lanes, but can also be to estimate the effect of a change in design, such as whether to construct a median or to improvethe shoulders. The calculation procedures used for operational analysis and for design are the same, and follow the principles outlined in Section 2.2.

This Chapter contains detailed step-by-step instructions to be carried out forthe operational analysis or design, using the same Forms IR-1, IR-2, IR-3 and IR-4 as for interurban roads. Blank forms for copying aregiven in Appendix 6:1.

For undivided motorways, calculations are carried out for bothdirections combined. For divided motorways calculations for operationalanalysis and design are carried out separately by direction.

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STEP A : INPUT DATA

STEP A-1 : GENERAL DATA

a) Segmentation

Divide the motorway into segments. A motorway segment is defined as alength of motorway having similar characteristics along its length. Points where road characteristics change significantly become segmentboundaries. Each segment is separately analysed. If several geometricalternatives (cases) are being explored for the segment, each case is given aunique code and is recorded into separate sets of input data forms (IR-1 and IR2). Separate analysis forms (IR-3 and if necessary IR-4) are also used for each case. If separate time periods are to be analysed, then aseparate case number must be assigned to each, and separate input dataforms and analysis forms should be used.

The studied motorway segment should be unaffected by any interchanges or ramps which might influence its capacity and level of performance.

Segments may be called 'general terrain segments' (the normal case) or 'specific grades', see b) below.

b) Specific grades

(Only applicable for two-lane undivided motorways MW 2/2 UD).

At this stage it must be decided whether any part of the motorway is a specific grade which requires separate operational analysis. This could bethe case if there is one or more continuous gradients along the motorwaywhich cause severe capacity or performance problems and whereimprovements to alleviate these problems are being considered (e.g.widening or providing a crawler lane). Each of such gradients could be designated a separate segment and each analysed individually under theprocedures for 'analysis of specific grades', given below. The segmentwould be from the base of the grade to its brow. Generally, specificgrades should not be shorter than about 400m but have no upper lengthlimit. However, specific grade segments should be continuous upgrade(downgrade in the opposite direction) i.e. with no flat or downhill sections, and should have a gradient of at least 3 per cent on average over the wholesegment: the gradient need not be constant over the whole segment length. Short grades (up to about 1 km in length) would normally only be analysedseparately if very steep, while longer grades may need separate analysiseven if less steep, because of their progressive speedreduction effects,especially on heavy vehicles.

Even if a steep grade causes significant capacity and performance problems, itwould not be designated a 'specific grade' if one or all of the followingconditions apply:

- only a planning analysis is needed, not an operational analysis;- if there is no intention to consider modifications to geometric

design to alleviate the effects of the grade;

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- if the horizontal curvature is great enough to cause it, in the opinion of the engineer, to be the single main determinant of capacity and performance, rather than the gradient.

In these cases a separate 'specific grade' segment would not be defined and the gradient would be subsumed in the general analysis of the longer segment of which it forms a part, with gradient characteristics being accounted for by terrain type.

c) Segment identification data

Fill in the following general data in the top of Form IR-1:

- Date (day, month, year) and 'Handled by' (enter your name).

- Province in which the segment is situated.

- Link number (Bina Marga or Java Marga), if available

- Segment code (e.g Km 3.250-4.750)

- Segment between ... (e.g. Lembang and Ciater)

- Administrative road class (Toll road, National, Provincial or Kabupaten)

- Road type: examples:

Four-lane two-way divided motorway: MW 4/2 DTwo-lane two-way undivided motorway: MW 2/2 UD

- Segment length (e.g. 1.500 km)

- Road functional class (usually 'arterial' for motorways)

- Time period to be analysed (e.g. Year 2000, a.m. peak hour)

- Case number (e.g. A2000:1)

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STEP A-2: GEOMETRIC CONDITIONS

a) Horizontal alignment

Make a sketch of the road segment using the allocated space in Form IR-1. Make sure to include the following information:

- Compass arrow showing North.

- Km-posts or other objects used to identify the location of the roadsegment.

- Sketch of the horizontal alignment of the road segment.

- Arrows identifying Direction 1 (normally North- or East bound) and Direction 2 (normally South- or West bound).

- Names of the places which the road segment passes/connects.

- Pavement markings such as lane markings, pavement edge line, centerline etc.

Fill in the following information in the boxes under the figure:

- Horizontal curvature for the studied segment (radian/km) (ifavailable).

b) Sight distance class

In the appropriate box under the horizontal alignment sketch, enter thepercentage of road segment length with a passing sight distance greater than or equal to 300 m (if available). From this information the Sight Distance Class(SDC) can be determined as shown in Table A-2:1 below, or it can beestimated by engineering judgement (if in doubt use default value = A for motorways). Enter the resulting SDC value in the box under the sketch of the horizontal alignment in Form IR-1.

Sight dsitance class

% of segment with sightdistance of at least 300 m

A > 70%B 30-70%C < 30%

c) Vertical alignment

Make a sketch of the vertical profile of the road in the same longitudinalscale as the sketch of the horizontal alignment above it. Indicate gradients in % if available.

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Fill in information regarding general terrain type by encircling theappropriate type (flat, rolling or hilly). If the segment is a specific grade,fill in information regarding average slope and length of the grade.

d) Terrain type

Fill in the information for terrain type by encircling the appropriate type (flat,rolling or hilly), using the information on horizontal curvature (rad/km)and on vertical rise and fall (m /km), together with Table A-2:2, to determinethe terrain type.

Terraintype

Rise + fall(m / km)

Horizontal curvature (rad / km)

Flat <10 <1.0Rolling 10-30 1.0-2.5Hilly >30 >2.5

Table A-2:2 Terrain types

If the rise and fall or horizontal curvature information is not available, useengineering judgement or the IRMS terrain type for the Bina Marga link(s) into which the segment falls.

e) Road cross section

Make a sketch of the road cross section and indicate effective (average)carriageway width, median width, effective (average unobstructed) inner and outer shoulder widths (if divided road). Observe that Side A and SideB are determined by the cross section reference line in the horizontalalignment sketch.

Figure A-2:1 Illustration of the geometric terms used for a divided road.

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Fill in the relevant geometric data for the studied segment in the spaces provided below the sketch. The geometric terms used are shown below. If aroad only has a shoulder on one side, the average shoulder width is equal to half of the width of that shoulder. For a divided road the mean shoulderwidth is calculated per direction as the average of the outer and innershoulder widths.

f) Road surface condition

Fill in the following information

Carriageway(s):

- Type of pavement (encircle. the appropriate answer).- Pavement condition (encircle the appropriate answer).- Road roughness (IRI value) if available.

Shoulders: (Inner (median) and outer (roadside) if divided road)

- Surface type (encircle the appropriate answer). - Mean vertical drop (difference between levels) between carriageway and

shoulders.- Shoulder usability (traffic, emergency stops only). The following

guidelines are used for this classification: Traffic: The shoulder is > 2 m and has the

same pavement quality as thecarriageway.

Parking or Emergency stop: Shoulder width < 2 m

g) Traffic control conditions

Fill in information regarding relevant applied traffic control measures on thestudied road segment such as:

- speed limit (km/h);- restrictions relating to specific vehicle types;- special gross-weight and/or axle load restrictions;- other traffic control devices/ordinances.

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STEP A-3: TRAFFIC CONDITIONS

Use Form IR-2 to record and reduce input data regarding light vehicle units (Ivu), traffic flow and traffic composition.

a) Light vehicle units (Ivu)

Two sets of lvu values for standard terrain types are given in the uppermost table in Form IR-2 for Light vehicles (LV), Medium heavyvehicles (MHV), Large buses (LB) and Large trucks LT (including truckcombinations). The speed lvu values are based on light vehicle speed ascriteria for equivalency, the capacity lvu values are based on a capacityequivalency for the total flow. The latter values are mainly used inanalysis regarding degree of bunching, and when the degree ofsaturation (Q/C) using the Ivu values exceeds 0.85. For specific grades, see under c) below. Two and three-wheeled vehicles are not permittedon motorways so no Ivu value is needed for them.

b) Traffic flow and composition for general terrain

ALTERNATIVE 1: Only AADT and traffic composition data is available.

1.a Enter the following input data in the appropriate boxes in Form IR-2:

- AADT (veh/day) for the studied year/case - K-factor (% vehicles during the design hour, normally = max.

hour)

l.b Calculate the design hourly flow (Q1, = AADT x K) and enter theresult in its box.

1.c Enter the traffic composition in % (based on veh/h) in Column (9) inthe table.

l.d Calculate the number of vehicles of each category as Qr, x % of each vehicle type and enter the results in Columns (3), (5) and (7),if necessary assuming a 50:50 directional split.

l.e Follow the procedures described in 2.b-d below.

ALTERNATIVE 2: Directional classified traffic flow counts/estimates are available for the design hour.

Enter the following input data in the table in Form IR-2:

2.a Hourly traffic flow values (Q) in veh/hour for each vehicle type inColumns (3), (5) and (7).

2.b Enter speed-based Ivu-values in Column (2) chosen from the leftside of the Ivutable in Form IR-2, and capacity based lvu from the right side of the Ivu'-table in Column (10).

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2.c Traffic flow values Q (lvu/h speed-based) to be entered in Columns (4),(6) and (8), and Q (lvu/h capacity-based) to be entered in Columns(11), (12) and (13). These values are obtained through multiplying the flow in veh/h in Columns (3), (5), (7) with the corresponding Ivu value in Column (2) and Column (10).

2.d Directional split (SP) is used for undivided motorways only. It iscalculated as the total flow (veh/h) in Direction 1 in Column (3) divided by the total flow in Direction 1+2 (veh/h) from Column (7).Enter the result in its box at the bottom of Column (7).

c) Traffic flow and composition for specific grades

For two-lane undivided motorways only: Follow the procedures described in Chapter 6, Step A-3 c).

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STEP B : ANALISYS OF FREE-FLOW SPEED Start at Step B-1 if the studied segment is a general terrain segment. If the segment is a specific grade (only applicable for two-lane undivided motorways), go directly to Step B6.

Use Form IR-3 for the analysis to determine the actual free-flow speed, with the inputdata from Step A (Forms IR-1 and IR-2).

FV = FVo+ FFVw

where:FV = Free-flow speed for actual conditions (km/h)FV0 = Base free-flow speed for pre-determined standard (ideal) conditions

(km/h)FFVw = Adjustment factor for effective carriageway and shoulder width (km/h)

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STEP B-1: BASE FREE-FLOW SPEED

Determine the base free-flow speed (FVO) for:

- light vehicles for flat terrain, and - light vehicles for actual terrain conditions

using Table B-1:1. Note that for two-lane two-way undivided motorways the base freeflow speed in flat terrain is also a function of sight distance class (from Form IR-1). If sight distance class is not known, assume SDC = B.

Enter these two base free-flow speed values into Columns (2) and (3) respectively of Form IR-3.

Note that only the values of free-flow speeds for light vehicles are used in thisManual. Free-flow speeds for the other vehicle classes shown in Table B-1:1 are for reference purposes only.

Base free flow speed FV0 km/hMotorway type/ Terrain type Light

vehiclesLV

LargebusesLB

Medium heavy vehiclesMHV

LargetrucksLT

Four-lane divided - Flat terrain 85 90 70 65- Rolling terrain 75 74 57 53- Hilly terrain 66 67 46 42Two-lane undivided- Flat terrain SDC: A 77 82 64 58" " SDC: B 75 79 62 57" " SDC: C 72 75 60 56- Rolling terrain 69 69 52 47- Hilly terrain 62 63 42 38

Table B-1:1 Base free-flow speed FV0 for motorways

The general terrain types are defined in Chapter 6, Section 1.3.

The free-flow speeds for six-lane motorways can be taken to be the same as for four-lane motorways in Table B-1:1.

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STEP B-2: SPEED ADJUSTMENT FACTOR FORCARRIAGEWAY AND SHOULDER WIDTH

Determine the adjustment factor FFVW (km/h) for carriageway and shoulder widthfrom Table B-2:1 based on the effective carriageway width (WC) and shoulder width (WS) recorded on Form IR-2. Enter the result in Column (4). Observe that for motorways, which normally have paved shoulders usable for traffic, the width of the shoulders shall not be added to the effective carriageway width.

FFVW,FLAT km/h

Average shoulder width (WS)(m)Motorway type

Effectivecarriagewaywidth (WC)

(m) 0 1 2

Four-lane divided Per lane3.25 -6 -5 - 43.50 -4 -2 -13.60 -2 -1 03.75 -1 0 1

Two-lane undivided Total6.5 -4 -2 -17.0 -2 0 17.5 1 1 2

Table B-2:1 Adjustment factor FFVW for the influence of carriageway and shoulder width on free-flow speed of light vehicles.

Note that the values in Table B-2:1 were derived for flat terrain. If the studied roadis not flat, an appropriate conversion is performed as described below:

For other terrain types an actual adjustment factor FFVW,ACT is calculatedthrough multiplication of the adjustment factor for flat terrain with the ratiobetween free flow speed for the actual terrain type and the free flowspeed for flat terrain as shown below:

FFVW,ACT = FFVW x FV0,ACT / FV0,FLAT

Enter the resulting, adjusted FFV value in Column (8) in Form IR-3.

Free-flow speed adjustment factors for motorways with more than four lanes(multi-lane) can be estimated using the figures given for four-lane motorways inthe table above.

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STEP B-3: DETERMINATION OF FREE-FLOW SPEED FOR ACTUAL CONDITIONS

The actual free-flow speed for the studied terrain type is obtained by adding the values in Column (3) and Column (8) and entering the result in Column (9).

The free-flow speed for other vehicle types can be estimated using the followingequation:

Example:

FVMHV = FVMHV,0 + FFV x FVMHV,0 /FV0

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STEP B-4: FREE-FLOW SPEED FOR SPECIFIC GRADES

Only for two-lane undivided motorways:

If the segment is not a specific grade, Step B-4 should be omitted.

The free-flow speeds for light vehicles on two-lane undivided motorways (MW 2/2UD) with specific grades must be calculated for each direction (uphill and downhill)separately. Use Form IR-4 when determining the free-flow speed for a specificgrade. Uphill = direction 1, downhill = direction 2.

1. Enter the values for the average slope and the length of the grade (from IR-1).

2. Determine base free-flow speed for flat conditions from Table B-1:1, and enter the results in Column (3) in separate rows for direction 1 and 2.

3. Determine the base uphill and downhill free-flow speeds FV0,UH and FV0,DHseparately from Table B-4:1 below. The speeds FV0,UH and FV0,DH are a functionof the gradient and length of the grade. Enter the results in Column (4) in the rowsfor both directions.

Direction 1, Uphill Gradient % Direction 2, downhill Gradient % Lengthkm 3 4 5 6 7 3 4 5 6 70.5 75.7 71.8 67.8 63.6 59.2 75.7 75.7 75.7 71.8 67.81.0 73.6 68.4 63.2 58.3 53.3 75.7 75.7 73.6 68.4 63.22.0 72.1 66.2 60.2 55.2 50.2 75.7 75.7 72.1 66.2 60.23.0 71.5 65.5 59.4 54.4 49.4 75.7 75.7 71.5 65.5 59.44.0 71.2 65.1 58.9 53.9 48.9 75.7 75.7 71.2 65.1 58.95.0 71.0 64.8 58.6 53.6 48.6 75.7 75.7 71.0 64.8 58.6

Table B-4:1 Base uphill free-flow speed FV0,UH and downhill free-flow speed FV0,DH for light vehicles in specific grades, MW 2/2 UD

4. Calculate the actual free-flow speed for light vehicles in the uphill anddownhill directions separately, using the adjustment factor described in StepB-2, and enter the result into Form IR-4 Column (5), using the rows for eachdirection.

The adjustment factors for each direction in Column (5) are thentransferred into the appropriate rows of Column (8).

The adjustment factor in Column (8) is applicable only to flat terrain andmust now be further adjusted for actual terrain, separately for the uphill anddownhill directions . This is done by multiplying the adjustment factors inColumn (8) by

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the ratio of base free-flow speed for actual terrain in Column (4) and the base freeflow speed for flat terrain in Column (3). This is the same process asdescribed in Step B-2 above. The resulting values are entered into the uphilland downhill rows of Column (9).

The final values for the free-flow uphill and downhill speeds (Column (4) + Column (9)) are entered into Column (10).

5. To calculate the combined speed consider the flow for light vehicles inthe two directions.

QLV1 is the light vehicle flow in direction 1 (uphill) QLV2 is the light vehicle flow in direction 2 (downhill)QLV = QLV1 + QLV2 is the light vehicle flow for both directions

The average free-flow speed for both directions FV is now calculated as:

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STEP C : ANALYSIS OF CAPACITY

If the segment is a specific grade on a MW 2/2 UD, go directly to Step C-5 anduse Form IR-4 rather than Form IR-3.

Use the input conditions determined in Steps A - C (Form IR-1 and IR-2) todetermine the capacity with the help of Form IR-3.

C = Co x FCW x FCSP

where:C = Capacity (Ivu/h)C0 = Base capacity for pre-determined (ideal) conditions (Ivu/h)FCW = Adjustment factor for carriageway widthFCSP = Adjustment factor for directional split (undivided motorways)

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STEP C-1: BASE CAPACITY

Determine the base capacity (C0) from Table C-1:1 and enter the value into Form IR-3,Column (11). (Observe that the effect of terrain type on capacity is also accounted forby the use of different lvu-values as described in Step A-3).

Motorway type/ Terrain type

Base capacity(lvu / h)

Comment

Four-lane divided Per lane- Flat terrain 2300- Rolling terrain 2250- Hilly terrain 2150

Two-lane undivided Total in both directions- Flat terrain 3400- Rolling terrain 3300- Hilly terrain 3200

Table C-1:1 Base capacity C„ for motorways

Base capacities for motorways with more than four lanes (multi-lane) can be estimatedusing the capacities per lane given in the table above, even if the lanes are of non-standard width (correction for width is made in Step C-2 below).

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STEP C-2: CAPACITY ADJUSTMENT FACTOR FORCARRIAGEWAY WIDTH

Determine the adjustment factor FCW for carriageway width from Table C-2:1 based on theeffective carriageway width (WC) (see Form IR-2) and enter the result in Form IR-3,Column (12). For motorways, which normally have paved shoulders usable for traffic, the width of the shoulders shall not be added to the effective carriageway width.

Motorway type Carriageway

width WC(m)

FCW(m)

Four-lane divided Per lane

3.25 0.953.50 0.983.6 1.003.75 1.03

Two-lane undivided Total both directions

6.5 0.967 1.00

7.5 1.03

Table C-2:1 Adjustment factor FCW for the influence of carriageway width on capacity.

Capacity adjustment factors for roads with more than four lanes (multi-lane)can be estimated using the figures per lane given for four-lane roads in the tableabove.

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STEP C-3: CAPACITY ADJUSTMENT FACTOR FOR DIRECTIONAL SPLIT

Determine the capacity adjustment factor for directional split (FCSP) from Table C-3:1 below based on the input data for traffic conditions from Form IR-2 Column (7), andenter the value into Column (13) in Form IR-3 (ONLY FOR UNDIVIDEDMOTORWAYS MW2/2 UD).

Directional split SP %-% 50-50 55-45 60-40 65-35 70-30

FCSPUndividedmotorways 1.00 0.97 0.94 0.91 0.88

Table C-3:1 Directional split capacity adjustment factor (FCSP)

STEP C-4: DETERMINATION OF CAPACITY FOR ACTUALCONDITIONS

Determine the capacity of the road segment for actual conditions with the help of thedata filled into Form IR-3 Columns (11) - (13) and enter the result in Column (16):

C = C0 x FCW x FCSP (Ivu / h) where:C = Capacity (Ivu/h)Co = Base capacity for pre-determined (ideal) conditions FCW = Adjustment factor for carriageway widthFCSP = Adjustment factor for directional split (undivided motorways)

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STEP C-5: CAPACITY FOR SPECIFIC GRADES

The capacity for a specific grade is calculated in essentially the same way as for general terrain segments above, but with different base capacity and in some cases with different adjustment factors. Form IR-4 should be used for the analysis of specific grades.

C = C0 x FCW x FCSP. (lvu/h)

The two-way base capacity (C0) is determined from Table C-5:1. Enter the value intoForm IR-4, Column (12).

Length of grade/Slope of grade

Base capacitylvu/h

Length < 0.5 km/all slopes 3300

Length < 0.8 km/Slope < 4.5% 3250

All other cases 3000

Table C-5:1 Base capacity Co for specific grades on two-lane motorways

The adjustment factor for carriageway width FCw is the same as in Table C-2:1 above for two-lane undivided motorways. Enter the value in Form IR-4, Column (13).

The capacity adjustment factor for directional split FCSP is determined in the same way as described in Chapter 6 (Interurban Roads) Step C-6 and is entered intoColumn (14).

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STEP D : LEVEL OF PERFORMANCE If the segment is a specific grade, go directly to Step D-4. Use the input conditions determined in Step A-3 (Form IR-2) and the free flow speed and capacity determinedin Steps B and C (Form IR-3) to determine degree of saturation, speed and travel time,and ratio of bunching. Use Form IR-3 for level of performance analysis.

STEP D-1: DEGREE OF SATURATION

SPEED-BASED DEGREE OF SATURATION

1. Read the total traffic flow value QV (lvu/h, speed-based) from Form IR-2 Column (8) for undivided roads, and from Columns (4) and (6) for each separate direction of a divided motorway and enter the value into Form IR-3 Column (21).

2. Using the actual capacity from Column (16) of Form IR-3, calculate the ratio between QV and C to determine the degree of saturation (DSV,speed-based) and enter the value into Column (22).

DSV = QV/C (speed-based lvu)

CAPACITY-BASED DEGREE OF SATURATION

3. Read the traffic flow value QC (Ivu/h, capacity-based) from Form IR-2 Column (13) for undivided motorways and Columns (11) and (12) fordivided motorways and enter the value into Form IR-3 Column (31).

4. Using the actual capacity from Column (16) of Form IR-3, calculate the ratio between QC and C to determine the degree of saturation (DSC,capacity-based) and enter the value into Column (32).

DSC = QC/C (capacity-based Ivu)

STEP D-2: SPEED AND TRAVEL TIME

.1 Determine the speed at actual traffic and geometric conditions:

- Select value for degree of saturation DS as follows: Use DSV, (speed-based) from Column (22), if it is < 0.85 Use DSC (capacity-based) from Column (32) if it is > 0.85 otherwise:

Use 0.85.

- Use Figure D-2:1 (two-lane undivided motorway) or Figure D-2:2(four-lane divided motorways) as follows:

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a) Enter with the chosen DS value on the horizontal (x) axle at thebottom of the figure.

b) Make a line parallel with the vertical (y) axle from this point until it intersects with the actual free-flow speed value from Form IR-3 Column (9).

c) Make a horizontal line parallel with the (x) until it reaches the vertical (y) axle at the left side of the figure and read a value for actual lightvehicle speed for the analysed conditions.

d) Enter this value into Column (23) in Form IR-3.

.2 Enter the length of the segment L (km) in Column (24) (from Form iR-j).

.3 Calculate the average travel time for light vehicles in hours for the studied case, and enter the result in Column (25):

Average travel time TT = L/V hours

Figure D-2:1 Speed as a function of Q / C for two-lane undivided motorways

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Figure D-2:2 Speed as a function of Q/C for four-lane, divided motorways

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STEP D-3: DEGREE OF BUNCHING (PLATOONING)

Determine the degree of bunching (DB) on two-lane, two-way undivided motorwaysbased on the degree of saturation DSC in Column (32) using Figure D-3:1 below, and enter the value into Column (33) in Form IR-3. Bunching is defined in this Manual as the ratio between the flow of vehicles (excluding motorcycles) with a time headway of < to 5 seconds to the nearest vehicle in front travelling in the same direction, and the total flow (veh/h) in the studied direction(s).

DBveh = (vehicles with headway <5 sec)/Q

Figure D-3:1 Degree of bunching on undivided motorways as a function of degree of saturation based on capacity (Qc/C)

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STEP D-4: SPEED AND TRAVEL TIME FOR SPECIFIC GRADES

For analysis of a specific grade on undivided motorways, follow Chapter 6 Step D-4 (Interurban Roads) but use Table D-4:1 below to determine speed at capacity,instead of the equivalent table in Chapter 6.

Uphill speed at capacity Gradient% L, km

0.5 1 1.5 2 > 2.5 3 46.0 42.5 40.5 39.5 38.54 37.5 34.5 32.5 31.5 31.05 32.0 29.0 27.0 26.5 26.06 27.0 25.0 23.5 22.5 22.07 23.5 21.0 20.0 19.5 19.0

Table D-4:1 Uphill speed at capacity VUHC for light vehicles on specific grades of two-lane two-way motorways.

If the grade has a climbing lane, consider the uphill direction as two lanes of a four lane undivided road in hilly terrain and perform the calculations as described inStep D-4 of Chapter 6 (Interurban Roads).

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STEP D-5: EVALUATION OF LEVEL OF PERFORMANCE

This Manual has been primarily designed to estimate consequences regardingcapacity and level of performance of a set of given conditions regardinggeometric road design, traffic and environment. Since the outcome usually cannot be predicted beforehand, it is quite likely that the user wants to revise some of theassumptions made regarding these conditions in order to get a desired level of performance regarding capacity and speed etc.

The quickest way to evaluate the results is to look at the degree of saturation (DS) forthe studied case, and to compare it with the annual traffic growth and the desired functional "life" of the road segment in question. If the obtained DS value is too high, the user might want to revise his assumptions regarding road cross section etc and make a new set of calculations. This will then require revision of the calculation formsused, or filling in a new set of forms with a new assigned case number.

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4. CALCULATION PROCEDURE FOR PLANNING ANALYSIS

For planning of motorways, the traffic and environmental data would be known in general, but not in detail, and forecast traffic flow would normally be given in AADT, rather than as peak hour flow. Consequently, certain assumptions aboutgeometric design, traffic and environment have to be made and it should be notedthat these assumptions do not always correspond to the motorway 'base cases'described in Section 2.4. The geometric assumptions for planning are more relatedto typical observed conditions thanto standard design.

The relationship between the flow in the peak hour or design flow (QD) and AADTmust also be assumed. This relationship is normally expressed as an 'AADT-factor' K as follows:

K = QD/AADT

Planning analyses are normally carried out for both directions combined, even if it isanticipated that the motorway will have a median. (There is no difficulty with this as a 50:50 directional split is assumed for planning).

4.1 BASIC ASSUMPTIONS FOR DIFFERENT MOTORWAYTYPES

4.1.1 Two-lane two-way undivided motorways (MW 2/2 UD)

The assumptions used for planning of two-lane, two-way undivided motorways are asfollows:

Motorway function: Arterial (national or provincial)

Cross section: 7 m carriageway, 2 m effective shoulder width on both sidesin flat and rolling terrain, 1.0 m in hilly.

Sight distance: 75% of the segment has more than or equal 300 m sight distance (SDC = A)


Environment: Interurban (mostly rural area)

Traffic composition: LV: 63%; MHV 25%: LB: 8%; LT+TC 4% (no MC)



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4.1.2. Four-lane, two-way divided motorways (MW 4/2 D)

The assumptions used for planning of four-lane two-way motorways are as follows:



Shoulders: Average 1.5 m effective shoulder width (inner = 0.5 m and outer = 2.5 m)/2 per direction in flat and rolling terrain, 1.0 m in hilly terrain (inner = 0.5 m and outer = 1.5 m)/2.

Median: Yes



Environment: Interurban (mostly rural area).

Traffic composition: LV: 63%; MHV 25%: LB: 8%; LT+TC 4% (no MC) K-factor:Design hourly volume = 0.11 xA A DT (K = 0.11) Directionalsplit: 50/50

4.1.3 Six-lane, two-way divided motorways (MW 6/2 D)

The assumptions used for planning of six-lane two-way motorways are as follows:



Median: Yes (6/2 D)

Shoulders: Average 1.5 m effective shoulder width (inner = 0.5 mand outer = 2.5 m)/2 per direction in flat and rolling terrain,1.0 m in hilly terrain (inner = 0.5 m and outer = 1.5 m)/2.



Environment: Interurban (mostly rural area).

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HCM: MOTORWAYS

Traffic composition: LV: 63%; MHV 25%: LB: 8%; LT+TC 4% (no MC)



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4.2 ANALYSIS OF MOTORWAY PERFORMANCE

On the basis of the assumptions recorded in Section 4.1 above, the procedures proposed for operation and design analysis have been applied to produce Table 4.2:1 below. This table relates AADT to the level of motorway performanceexpressed as

- Free flow speed (equal to speed at AADT = 0) - Degree of saturation (Speed-based: DSV = QV/C)

(Capacity-based: DSC = QV/C)- Speed (km/h) at different flow levels and degree of saturation Q/C- Degree of bunching (only for motorway type MW 2/2 UD)

If the base assumptions regarding K-factor and traffic composition are not valid for the studied case, the table can be entered using Design hourly flows (QD) asfollows:


- Calculate QD = AADT x K (veh/h)

- Calculate the P-factor for conversion from veh/h to lvu/h:

P = (LV% x lvuLV + MHV% x IvuMHV + LB% x IvuLB + LT% X IvuLT)/100

- Calculate Design hourly flow in light vehicle units:

QD = QAADT x K x P (Ivu/h)

Table 4-2:1 can be used in the following main ways:

a) To estimate the level of performance for different road types at given AADT or design hour (QD) levels. Linear interpolation can be done for flowvalues which fall between given values in the top of the table.

b) To estimate the level of traffic flow in AADT which can be accommodated by different road types within a permissible level of performance regarding degree of saturation, speed and degree of bunching.

No worksheet is needed to perform the above mentioned evaluations. However, if conditions are known to be significantly different from the assumed conditionsgiven in Section 4.1 above, then appropriate value(s) should be used and an operational/design analysis performed instead as described in Section 3. This would first require conversion of AADT to peak hour, using AADT-factor(default: K = 0.11). Examples of cases where an operational analysis would beneeded are:

- if the traffic is expected to be quite different from the assumed values, e.g. K-volue, traffic composition, directional split. Form IR-2 will then have to beapplied to calculate design hourly flow, and Form IR-3 should be used tofacilitate the colcula, tion of the different measures of performance..

- if the carriageway width differs very much for the planned segment to beanalysed;

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HCM: MOTORWAYS

- if the horizontal and vertical alignment differs very much from the assumed,general terrain types.

MOTORWAYS

Table 4.2:1 Level of performance as a function of motorway type and AADT

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5. WORKED EXAMPLES

5.1 EXAMPLE 1: OPERATIONAL ANALYSIS OF A TWO-LANE TWO-WAY UNDIVIDED MOTORWAY (MW 2/2 UD)

CONDITIONS

CASE A:

Geometry : 6.80 m effective carriageway width (undivided)1.0 m effective shoulder on both sides (level with road) 50 % of the segment with sight distance > 300 m (SDC = B)

Terrain : Rolling terrain

Traffic : Classified flow count March 1994 both directions: Vehicle type Veh/max. hour - Light vehicles: 1,287

- Medium heavy vehicles: 297 - Large buses: 305

- Large trucks + truck comb.: 102Directional split of 55 - 45

Environment : Rural area south of Semarang.

Questions:

1. Calculate for the actual conditions and time (March 1994):

CASE A:1994- Actual free-flow speed

- Actual capacity- Degree of saturation: speed-based and capacity-based

- Actual speed- Degree of bunching

2. Predict the effect on free-flow speed, capacity, degree of saturation, actual speed and degree of bunching of the following measure (other conditionsunchanged):

CASE B:1994- Widening of the existing carriageway to 7.0m and construction of a second

7.0 m carriageway with 2.5 m outer shoulders and 0.5 m inner (medianside) shoulders so that the road becomes a four-lane divided motorway (MW 4/2 D).

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Solutions (see forms below)

1. CASE A: 1994

Actual free-flow speed: 68 km/h Actual capacity: 3188 lvu / h Degree of saturation, speed-based: 0.84Degree of saturation, capacity-based: 0.77Actual speed: 45 km/hDegree of bunching: 0.85

2. CASE B: 1994

The analysis must be carried out separately by direction for the new 4/2 Dmotorway. However, if both carriageways have identical geometry, it is often enough (as in this case) to analyse only the direction carrying the highest flow(in this case called 'direction 1'). (Note that the average shoulder width per carriageway is (2.5 + 0.5)/2 metres). The results for direction 1 are:

Actual free-flow speed: 74 km/hActual capacity: 4410 lvu/h Degree of saturation, speed-based: 0.33 Actual speed: 69 km/hDegree of bunching (and capacity-based DS): not applicable to 4-lane motorways.

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Form IR - 1Date: AUGUST 291994 Handled by: EN

Province: CENTRAL JAVA Cheked by: NWM

Link no : NA Segment code: STA 5.8

Segment between GOMBEL and MANYARAN

Admin. Road class: TOLL ROAD Road type: MW 2/2 UD




Time period: MARCH 1994 Case number: A 1994 : 1



RoadsideDevelopment (%) NA NA NA

Vertikal alignment



Cross section


Effective Carriageway Witdh (Wc , m): 3.4 3.4 6.8

Average effective shoulder witdh (Ws , m) 1.0 1.0 2.0 1.0




IRI : NA



Surface type: (Flexible = F, Stone =,Earth = E) NA F NA F


Usability: (Traffic=T, Parking=P, Emergency stop=E) NA F NA F




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Form IR - 2 ITERURBAN ROADS & MOTORWAYS Date : AUGUST 29,1994 Handled by: EN

FROM IR-2 : INPUT DATA Link no : NA Checked by: NWM

TRAFFIC FLOW Segment code : STA 5.8

SIDE FRICTION Case number : A 1994 :1





1.01.01.01.0

1.51.52.03.5

1.01.21.31.5

3.22.74.05.5

1.01.01.01.0

1.21.21.31.5

1.51.51.72.0

2.02.02.53.0








(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13)

LVMHVLBLT

1.02.01.34.0

1.287297305102

1.287594397408

1.01.31.72.5

1.287386519255

Total 1.991 2.686 2.447

MC

Directional split SP = Totals (3)(7) x 100 (%) 55 MC ratio = Qmc/Qc

Pv (speed-based) = Totals (8)(7) 1.35 Pc (capacity-based) = totals (13)(7) 1.23

Side friction Class




FrequencyOf events

Weightedfrequency


PEDPSVEEVSMV

0.60.81.00.4



Total :



50 – 149 150 – 249 250 – 349

> 350



VLLMH

VH

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Form IR - 3INTERURBAN ROADS & MOTORWAYS Date : AUGUST 29 1994 Handled by : ENFORM IR-3 : ANALYSIS Link no : NA Cheked by : NWM

SPEED, CAPACITY Segment code : STA 5.8

BUNCHING Case number : A 1994 : 1 & B 1994 : 1



Km/hCaseNo.

Flatterrain

Actualterrain


Table B-2:1

Side friction FFVsf

Table B-3:1


Table B-4:1

TotalFFV

(4)+(5)+(6)


terrainFFVact

(7) x (3) / (2)km / h


FVact

(3) + (8)km/h

(1) (2) (3) (4) (5) (6) (7) (8) (9)

A1994:1B1994:1

7585

-1.2-1.5

NANA

NANA

-1.2-1.5

-1.1-1.3

-1.1-1.3

67.973.7



CaseNo.

Base CapacityCo

Table C-1:1Ivu/h


Table C-2:1


Table C-3:1


1 – Qmc/Qc

Side friction FCsf

Table C-4:1


(11) x (12) x (13) x (14) x(15)

(10) (11) (12) (13) (14) (15) (16)

A1994:1B1994:1

3.3004.500

0.9960.98

0.97NA NA NA 3.188

4.410


CaseNo.

Traffic flowQv

Speed-basedIvu/h

Degree ofsaturation

DSv = Qv/C (21)/ (16)

ActualSpeed VIv

Fig D-2:1 or 2 Km/h

RoadSegmentLength L

km

Travel time TT

(24) / (23)h

(20) (21) (22) (23) (24) (25)

A1994:1B1994:1

2.6861.477

0.840.33

4569

1010

0.2220.145

Degree of bunching

CaseNo.

Traffic flowQc

Speed-basedIvu/h

Degree ofsaturation

DSv = Qv/C (31)/ (16)

Degree ofBunching

DBFigure D-3:1

(30) (31) (32) (33)

A1994:1 2.447 0.77 0.85

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5.2 EXAMPLE 2: PLANNING ANALYSIS

CONDITIONS

CASE A:

Geometry: Four-lane divided motorway with design according to thestandard case documented in Chapter 7 Section 4.1.2.

Terrain : Flat terrain

Traffic : AADT 50,000 year 1994 K-factor 0.10

Assumed traffic composition (excl MC): Vehicle type % - Light vehicles: 60

- Medium heavy vehicles: 25 - Large buses: 10

- Large trucks + truck comb.: 5Directional split of 50 - 50Annual traffic increase: 10%

Environment : Rural area east of Bekasi.

Questions:

1. What are the current operating characteristics of the motorway during the design hour traffic (degree of saturation, actual speed)?

2. Which year will it be necessary to widen the motorway to six lanes to maintain an operating speed during design hour conditions of at least 70 km/h.

Solutions:

1. Conditions are very similar to the assumed case for planning analyses,even though the K factor is somewhat different, so Table 4-2:1 can be used as it stands, giving the following result:

Actual speed: 67 km/hDegree of saturation: 0.73

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However, better estimates may be obtained as follows:

AADT = 50,000 veh/day; K = 0.10From Table 4.2:1 with K = 0.11

11.010.0AADT = x 50,000 = 45,500

11.010.0Degree of saturation = x0.73=0.66

Actual speed = 69 km/h

2. From Table 4-2:1 it can be seen that the speed now (1994) is < 70 km/h. Asthe desired speed = 70 km/h, the motorway must be widened to MWW 6/2 D at year NOW. At the current AADT of 50,000 (x 0.10/0.11 = 45,500) this will give a speed of 76 km/h and a degree of saturation of 0.44.

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6. REFERENCES

R1. TRB Highway Capacity Manual. Transportation Research Board, Special Report 209;Washington D.C. USA 1985.

R2. May, A.D. Traffic Flow Fundamentals.Prentice-Hall, Inc; 1990.

R3. Easa, S.M.May, A.D.

Generalized Procedure for Estimating Single-and Two-Regime Traffic-Flow Models.Transportation Research Records 772;Washington D.C. USA 1980.

R4. Hoban, C.J. Evaluating Traffic Capacity and Improvementsto Road Geometry.World Bank Technical Paper Number 74;Washington D.C. USA 1987.

R5. OECD Traffic Capacity of Major Routes.Road Transport Research; 1983.

R6. Brannolte,U.(editor)

Highway Capacity and Level of Service. Proceedings of International Symposium on Highway Capacity, Karlsruhe; RotterdamNetherlands 1991.

R7. McShane, W.R.Roess, R.P.

Traffic Engineering. Prentice-Hall, Inc; 1990.

R8. Black, J.A.,Westerman, H.L. Blinkhorn, L. McKittrick, J.

Land Use along Arterial Roads: Friction and Impact.The University of New South Wales; 1988.

R9. McLean, J.R. Two-Lane Highway Traffic Operations. Theoryand Practice. Gordon and Breach Science Publisher; 1989.

R10. TRB Highway Capacity Manual (Revised Chapter 7:Multi-lane Rural and Suburban Highways).Transportation Research Board; WashingtonD.C. 1992.

R11. NAASRA Guide to Traffic Engineering Practice.National Association of Australian State RoadAuthorities; 1988.

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R12. Directorate Generalof Highways

Standard Specification for Geometric Design ofInterurban Roads. Ministry of Public Works; 1990

R13 Ministry of Public Works Keputusan Menteri Pekerjaan Umum Nomor 552/KPTS/1991 tentang Penetapan Ruas-RuasJalan sebagai Jalan Nasional Indonesia. Jakarta; 1991.

R14 Government of Indonesia Undang-Undang Republik Indonesia No. 13 Tahun 1980 tentang Jalan.

R15 Directorate General ofHighways

Peraturan Pemerintah Republik IndonesiaNornor 26 Tahun 1985 tentang Jalan. Ministry of Public Works; 1985.

R16 Government of Indonesia Undang-Undang Republik Indonesia No. 14Tahun 1992 tentang Lalu-Lintas & AngkutanJalan.

R17. Government of Indonesia Peraturan Pemerintah Republik Indonesia No. 8Tahun 1990 tentang Jalan Tol.

R18 Akcelik, R Proceeding of the Second International Symposium on Highway Capacity. TRBCommittee A3A10, Sydney August 1994.

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