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(CIVL262)2009_s_ CIVL262-Quiz5-solution_by_PPSpider.pdf
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CIVL 262 C Introduction to Transportation System Tutorial Quiz 5 13 Mar2009
Name : Student ID : Level of Service
QUESTION 1
A four-lane freeway (two lanes in each direction) is located on a rolling terrain and has a design speed of 60 mph, 12ft lanes, and no lateral obstructions within 8ft of pavement edges. The traffic stream consists of cars and trucks only (no buses or recreational vehicles). A weekday peak-hour volume of 1800 vehicles is observed with 500 arriving in the most congested 15-min period. If a level of service no worse than C is desired, determine the maximum number of trucks that can be present in the peak-hour traffic volume.
Solution:
1800
The peak hour factor PHF ==0.9
60500
15 V 1800
q = /The service flow SF == = 2000veh h
PHF 0.9
From Table 2.2, the ideal lane flow for LOS C is MSFC =1400 //
pc h lane .
From Table 2.3, the adjustment factor fw is equal to 1.0.
The passenger car equivalent for trucks in rolling area ET is 4.0.
11
f ==
hv 1+PE( .1) 1+P (4.0 .1)
TT T
1
* N w hv 2000 PTSince qq= ff . i.e. =1400 2 1.0 , we get =13.333% .
1+PT (4.0 .1)
So the maximum number of trucks that can be present in the peak-hour traffic volume is 180013.333% =240 .