CE 408 Highway and Traffic Engineering

Transportation is a way of moving people or things from one place to another.

What is Transportation?

Land (roads and railways)

Water(seaports)

Air(airports)

Modes of Transportation

Modes of Transportation

Highway engineering is an engineering discipline branching from civil engineering that involves the planning, design, construction, operation, and maintenance of roads, bridges, and tunnels to ensure safe and effective transportation of people and goods

Highway Engineering

Traffic engineering is a branch of civil engineering that uses engineering techniques to achieve the safe and efficient movement of people and goods on roadways.

It focuses mainly on research for safe and efficient traffic flow, such as road geometry, sidewalks and crosswalks, segregated cycle facilities, shared lane marking, traffic signs, road surface markings and traffic lights.

Traffic engineering deals with the functional part of transportation system, except the infrastructures provided.

Traffic Engineering

There are three main elements of automobile transportation: The road users (Drivers and pedestrians) The vehicle The road way and geometric design of roads

Elements of Transportation

Classification of Highways

National highway act ( 1956 )

Depending on weather• All weather roads• Fair weather roads

Depending the type of Carriage way• Paved roads• Unpaved roads

Depending upon the pavement surface• Surfaced roads• Un surfaced roads

Based on the Traffic Volume Heavy Medium Light

Cont…,

Based on modified system of Highways classification Primary

Expressways National Highways

SecondaryState Highway Major District Roads

TertiaryOrdinary district Roads Village Roads

Expressways Heavy traffic at high speed (120km/hr) Land Width (90m) Connects major points of traffic generation No slow moving traffic allowed No loading, unloading, parking.

National Highways The National Highways of Pakistan consists of all

public highways maintained by National Highways Authority under the Ministry of Transport.

It maintains over 12,000 kilometres (7,500 mi) of roadways organised into various classifications which crisscross the country and provide access to major population centres.. 

All national highways in Pakistan are pre-fixed with the letter 'N' (for "National") followed by the unique numerical designation of the specific highway (with a hyphen in the middle), e.g. "N-5". Each numerical designation is separated by five numerals, i.e. N-5, N-10, N-15, etc.

State Highways

They are the arterial roads of a state, connecting up with the national highways of adjacent states, district head quarters and important cities within the state.

Major District Roads

Important roads with in a district serving areas of production and markets , connecting those with each other or with the major highways.

Other district roads

Roads serving rural areas of production and providing them with outlet to market centers or other important roads like MDR or SH.

Village roads They are roads connecting villages or group

of villages with each other or to the nearest road of a higher category like ODR or MDR.

Urban Road Classification ARTERIAL ROADS SUB ARTERIAL COLLECTOR LOCAL STREET PATHWAY DRIVEWAY

All roads

arterials

principle

Full control

interstates

Freeways/expresways

uncontrolled

minor

Non arterials

local collector

major

minor

ARTERIAL

Arterials primarily serve long-distance travel and are typically designed as either access controlled or partially access controlled facilities with limited locations at which vehicles can enter or exit the roadway (typically via on- or off-ramps).

Design Speed : 80km/hr Land width : 50 – 60m Divided roads with full or partial parking Pedestrian allowed to walk only at

intersection

SUB ARTERIAL

Less mobility than arterial. Design speed : 60 km/hr Land width : 30 – 40 m

Collector Street As their name implies, Collectors “collect” traffic

from Local Roads and connect traffic to Arterial roadways.

Collector routes are typically shorter than Arterial routes but longer than Local Roads.

(Collects and distributes traffic from local streets Provides access to arterial roads Located in residential, business and industrial

areas. Full access allowed. Parking permitted. Design speed : 50km/hr Land Width : 20-30m

Local Street

Design Speed : 30km/hr. Land Width : 10 – 20m. Primary access to residence, business or

other abutting property Less volume of traffic at slow speed Origin and termination of trips. Unrestricted parking, pedestrian

movements. (with frontage access, parked vehicle, bus stops and no waiting restrictions)

1) Provisional alignment Identification ( Map study)

2) Reconnaissance survey

3) Preliminary survey

4) Final location to determine center line and detailed survey

Engineering Surveys for Highway locations

Art of observing and making measurements of relative portions of natural and manmade features on the surface of earth and plotting these measurements to some suitable scale to form a map.

SURVEY

Highway surveys involve measurement and calculation of distances, angles (horizontal andvertical) and elevations. The data is then used to form a base map

with contour lines and longitudinal cross-sections.

SURVEY FOR A HIGHWAY

Three major categories1. Ground SurveysBasic equipment is used for location survey Measuring Tape. Levels. Theodolite. Electronic distance measuring devices

(EDM’s).

SURVEYING TECHNIQUES

2. Remote Sensing Measurement of distances and elevations

by using devices located above the surface of earth.

Data is collected through airplanes and satellites using global positioning systems (GPS).

Photogrammetry (data is obtained with the help of aerial photographs) is the most commonly used technique.

Cont..,

3. Computer Graphics Available/collected data is compiled and

stored in the electronic form. Photogrammetric and general survey data

is combined digitally with the help of softwares.

The files can then be plotted in the form of maps.

Cont..,

Location controls are basically the factors that effects the selection of location of a highwayMajor factors are: Topography. Soil Characteristics. Environmental factors (noise and air

pollution). Economic factors.

LOCATION CONTROLS

Highway location process have four phases Desk study of available data/information Reconnaissance survey Preliminary location survey Final location survey

HIGHWAY LOCATION SURVEY/PROCESS

Available data in the form of reports, maps,aerial photographs and charts is studied.

Data is obtained form government authorities e.g. transport department (NHA), geological survey of Pakistan etc.

Similarly, information is required to be obtained on hydrology, mining, agriculture and weather.

DESK STUDY OF AVAILABLE DATA

Data is obtained on the following characteristics: Engineering (topography, geology, traffic

volume and climate) Social (land use trends and zoning) Environmental (air, noise and water

pollution, wildlife, historic and archaeological sites)

Economic (construction cost, agricultural, commercial and industrial trends)

Cont..,

“Reconnaissance is the process of identifying several possible routes & evaluating the feasibility of these routes for a highway between specific points” Aerial photographs are often used for the

purpose, especially for rural areas.

RECONNAISSANCE SURVEY

Feasible routes are identifies by keeping in mind the following factors Terrain and soil conditions. Serviceability of route to industrial and

residential areas. Crossing of other transportation facilities

like rivers, rail and highways. Route directness.

Cont..,

Identification of control points for each feasible/selected route.

Routes are then plotted on a map.

Cont..,

The position of the feasible routes are set as closely as possible by Establishing all control points. Determining preliminary vertical and

horizontal alignments of each control point Economic and environmental feasibility of

the routes The best route is then selected as the

preliminary alignment for the highway.

PRELIMINARY LOCATION SURVEY

Initial cost of the project and future economic effects

Road user cost Construction cost Road user benefits Economic drawbacks from the projectInformation also helps in deciding the type of highway for a particular route.

Economic Evaluation

Environment Includes plant animals Human community Effects on quality of life for all (animals and

human being)

Environmental Evaluation

An environmental impact statement should be submitted which should include Available alternatives Assessment of all positive and negative

impacts Short and long term effects Unavoidable adverse environmental effects Use of natural resources Each route should be studied

e.g. Positive and negative effects of at grade or grade seperated intersection.

Environmental Evaluation

Detailed layout of the selected route is carried out at this stage Centreline of the road. Horizontal and vertical alignment. Property lines. Intersecting roads. Position of structures and drainage

channels.

FINAL LOCATION SURVEY

DETAILED SURVEY FOR FINAL LOCATION

Transferring the alignment on to ground.

Detail Survey – levelling work for longitudinal and transverse direction.

Intervals for cross sectional levellingPlain 50 – 100mRolling 50 – 75mBuilt up 50mHilly 20m

Soil Profile

Factors that effect location of highway in urban areas Connection to local streets (which street to

connect,traffic flow) Right-of-way acquisition (land cost, road on

elevated structures, noise and aesthetics) Coordination with other transportation systems Provisions for bicycles and pedestrians

(sidewalks,crosswalks, traffic control devices, ramps, bicycle path)

LOCATION OF HIGHWAY IN URBAN AREAS

Comparison of Conventional and Modern Methods of SurveyingElements of comparison

Conventional Modern

Maps- Base material

Topo sheets RS data, Aerial Photos, Satellite Imageries

Instruments Chains, Tapes, Theodolite, Dumpy levels

EDM, Total Station, GPS, Auto and Digital Level, Photogrammetry.

Accuracy Chain/Tape 1 in 3000 to 1 in 30,000Tacheometer 1 in 1000 to 1 in 10,000

EDM/TS 1 in 10000 to 1 in 1,00,000Photogrammetry. 1 in 10000 to 1 in 1,00,000

Plotting CAD Systems Software

Errors Human errors Closing Errors hence re measuring is required.