Example of Multilane Highway LOS

BFC 30302

MULTILANE HIGHWAY CAPACITY ANALYSIS EXAMPLE A 1.57-km segment of an east-west five-lane highway with two travel lanes in each direction is separated by a two-way right-turn lane (TWRTL). Given, -

Rolling terrain, 83.0-km/h 85th-percentile speed, 3.6-m lane width, 1,500-veh/h peak-hour volume, 6 percent trucks and buses, 8 access points/km (westbound), 6 access points/km (eastbound), 0.90 PHF, 3.6-m and greater lateral clearance for westbound and eastbound

What is the LOS of the highway on level terrain during the peak hour? Solution BFFS = 83.0 – 3.0 = 80.0 km/h Eastbound fLW = 0.0 (from Table 2.1) fLC = 0.0 (from Table 2.2) fM = 0.0 (from Table 2.3) fA = 4.0 (from Table 2.4) FFS = BFFS – fLW – fLC – fM – fA = 80.0 – 0.0 – 0.0 – 0.0 – 4.0 = 76.0 km/h PT = 0.06 ET = 2.5 (from Table 2.5) 1 1 fhv = = = 0.9174 1  PT (E T  1) 1  0.06(2.5  1) fp = 1.0 (assuming all are regular drivers) V = 1,500 PHF = 0.90 N=2

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vp =

V 1,500 = = 909 pc/h/ln PHF  N  fHV  fp 0.90  2  0.9174  1.0

Density =

vp S

=

909 = 12.0 pc/km/ln 76

LOS  LOS C (using Figure 2.3)

Westbound fLW = 0.0 (from Table 2.1) fLC = 0.0 (from Table 2.2) fM = 0.0 (from Table 2.3) fA = 5.3 (from Table 2.4) FFS = BFFS – fLW – fLC – fM – fA = 80.0 – 0.0 – 0.0 – 0.0 – 5.3 = 74.7 km/h PT = 0.06 ET = 2.5 (from Table 2.5) 1 1 fhv = = = 0.9174 1  PT (E T  1) 1  0.06(2.5  1) fp = 1.0 (assuming all are regular drivers) V = 1,500 PHF = 0.90 N=2 vp =

V 1,500 = = 909 pc/h/ln PHF  N  fHV  fp 0.90  2  0.9174  1.0

Density =

vp S

=

909 = 12.2 pc/km/ln 74.7

LOS  LOS C (using Figure 2.3)

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Table 2.1

Table 2.2

Adjustment for Lateral Clearance

Table 2.3

Table 2.4

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Adjustment for Lane Width

Adjustment for Median Type

Adjustment for Access Point Density

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Table 2.5

Passenger Car Equivalents on Extended General Highway Segments

Table 2.6

Passenger Car Equivalents for Trucks and Buses on Uniform Upgrades

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Table 2.7

Passenger Car Equivalents for Trucks and Buses on Downgrades

Table 2.8

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LOS Criteria for Multilane Highways

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Figure 2.3

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Speed-Flow Curves with LOS Criteria

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