Topic 6 - Uninterrupted Facilities

8/10/2019 Topic 6 - Uninterrupted Facilities

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CEE 362CEE 362 Spring 2006Spring 2006 Instructor: Zong TianInstructor: Zong Tian

Topic 6Topic 6Uninterrupted FacilitiesUninterrupted Facilities

(Chapter 9)(Chapter 9)


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Traffic FacilitiesTraffic Facilities

Uninterrupted FacilitiesUninterrupted Facilities TwoTwo--lane highwayslane highways

MultiMulti--lane highwayslane highways

Expressways and FreewaysExpressways and Freeways

Interrupted FacilitiesInterrupted Facilities IntersectionsIntersections

ArterialsArterials


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Uninterrupted FacilitiesUninterrupted Facilities

Multilane HighwaysMultilane Highways Speed limits: 40 ~ 55 mphSpeed limits: 40 ~ 55 mph

Traffic volume range: 15,000 to 40,000 per dayTraffic volume range: 15,000 to 40,000 per day

Partial access controlPartial access control

Divided or undividedDivided or undivided

FreewaysFreeways Speed limits: 60 ~ 75 mphSpeed limits: 60 ~ 75 mph

FullFull--access control (except freeway ramps)access control (except freeway ramps)

Divided with medianDivided with median

Minimum two lane each directionMinimum two lane each direction


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Freeway FacilitiesFreeway Facilities

Freeway segmentsFreeway segments

Basic

Off-ramp

On-ramp

Weaving

Basic

Basic


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Basic Sections: LOSBasic Sections: LOS(HCM Chapter 23)(HCM Chapter 23)


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Prevailing ConditionsPrevailing Conditions

12 ft lane12 ft lane

Lateral clearance is 6 ft or greaterLateral clearance is 6 ft or greater

Passenger car onlyPassenger car only

Interchange spacing is at least 2 miles apart (0.5Interchange spacing is at least 2 miles apart (0.5interchange per mile)interchange per mile)

Five lanes each direction for urban freewayFive lanes each direction for urban freeway Grades do no exceed 2 percentGrades do no exceed 2 percent

Commuter driversCommuter drivers


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LOS ProcedureLOS Procedure

Step 1: Determine FreeStep 1: Determine Free--flow Speed (FFS)flow Speed (FFS)

Step 2: Determine volume (pc/Step 2: Determine volume (pc/h/lnh/ln))

Step 3: Calculate density,Step 3: Calculate density, kk

Step 4: Determine LOS (Table 9.33)Step 4: Determine LOS (Table 9.33)


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Step 1: Determine FreeStep 1: Determine Free--flow Speed (FFS)flow Speed (FFS)

IDNLCLWf ffffBFFSuFFS ==

BFFSBFFS 70 (urban), 75 (rural)70 (urban), 75 (rural)ffLWLW (Table 9.34)(Table 9.34)

ffLCLC (Table 9.35)(Table 9.35)

ffNN (Table 9.36)(Table 9.36)

ffIDID (Table 9.37)(Table 9.37)


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Example 9.13Example 9.13

NN = 3;= 3;

LWLW = 11 ft;= 11 ft;

LCLC = 3 ft;= 3 ft;

IDID = 1.5 per mile= 1.5 per mile


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Step 2: Determine volume (pc/Step 2: Determine volume (pc/h/lnh/ln))

))()()(( HVpp

ffNPHFqq =

ffpp 0.85 ~ 1.00, 1.00 for commuter traffic0.85 ~ 1.00, 1.00 for commuter traffic

EETT,, EERR (Tables 9.25, 9.26, 9.27, 9.28)(Tables 9.25, 9.26, 9.27, 9.28)

)1()1(11

++

=

RRTT

HVEPEP

f


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EETT and Eand ERR Based onBased on

Types of Freeway SegmentsTypes of Freeway Segments

Extended Segments (Table 9.25)Extended Segments (Table 9.25) GradesGrades 3% but less than3% but less than mile, ormile, or

GradesGrades < 3% and less than< 3% and less than milemile

Segments with Specific GradesSegments with Specific Grades

(Tables 9.26 and 9.27)(Tables 9.26 and 9.27) Segments with Specific Downgrades (Table 9.28)Segments with Specific Downgrades (Table 9.28)

Composite GradeComposite Grade Two or more consecutive upgradesTwo or more consecutive upgrades

Grades < 4% or length < 4000 ft (average technique)Grades < 4% or length < 4000 ft (average technique)

Otherwise, use truck performance curvesOtherwise, use truck performance curves


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Grade: 3%Grade: 3% -- 2000 ft; 2%2000 ft; 2% -- 1500 ft1500 ft;;

PPTT

= 6%;= 6%;

PPRR = 10%;= 10%;


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Step 3: Calculate density,Step 3: Calculate density, kk

f

p

u

qk =

Step 4: Determine LOS (Table 9.33)Step 4: Determine LOS (Table 9.33)


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qq = 3000= 3000 vphvph;;PHF = 0.85;PHF = 0.85;

Trucks = 12%Trucks = 12%LWLW = 11 ft;= 11 ft;LCLC = 6 ft;= 6 ft;IDID = 1 per mile= 1 per mile

Terrain = levelTerrain = levelffpp = 1.0= 1.0


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ApplicationsApplications

Determine LOS, givenDetermine LOS, given qq,, NN, and, and FFSFFS

Determine Speed, givenDetermine Speed, given qq,, LOSLOS, and, and FFSFFS

Determine q, givenDetermine q, given LOSLOS, and, and FFSFFS

Determine N, givenDetermine N, given qq,, FFSFFS, and, and LOSLOS

Topic 6 - Uninterrupted Facilities

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