Traffic and Highway Engineering
5th Edition
ISBN: 9781305156241
Author: Garber, Nicholas J.
Publisher: Cengage Learning
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Chapter 9, Problem 7P
To determine
The number of lanes required to provide LOS C.
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An urban freeway is to be designed using the following information.
AADT = 52,500 veh/day
K (proportion of AADT occurring during the peak hour):
D (proportion of peak hour traffic traveling in the peak direction):
Trucks:
PHF = 0.94
Lane width:
Shoulder width:
Total ramp density:
Terrain:
3
Determine the number of lanes in the peak direction required to provide LOS C. (Assume commuter traffic and assume no RVs.)
lanes.
0.12
0.65
8% of peak hour volume
demand flow rate
12 ft
10 ft
0.5 interchange/mile; all interchanges are to be cloverleaf interchanges
rolling
HV'
Show all calculations required. (Calculate your answers for the peak direction only. Enter fy, the peak hour volume in veh/h, the free flow speed in mi/h, the demand flow rate in pc/h/In, the mean speed in mi/h, and the density in pc/mi/ln.)
fHV
peak hour volume
0.893
free flow speed
mean speed
density
6300
X
Your response differs from the correct answer by more than 10%. Double check your calculations. veh/h
1500
X
Your…
An urban freeway is to be designed using the following information.
AADT = 51,500 veh/day
K (proportion of AADT occurring during the peak hour): 0.11
D (proportion of peak hour traffic traveling in the peak direction):0.65
Trucks: 8% of peak hour volume
PHF = 0.94
Lane width:12 ft
Shoulder width:10 ft
Total ramp density:0.5 interchange/mile; all interchanges are to be cloverleaf interchanges
Terrain:rolling
Determine the number of lanes in the peak direction required to provide LOS C. (Assume commuter traffic and assume no RVs.)_______
calculations required Calculate your answers for the peak direction only.
Enter fHV,
the peak hour volume _____veh/h
the free flow speed _______ mi/h
the demand flow rate i_______ pc/h/ln
the mean speed ________mi/h
the density ______ pc/mi/ln.)
An existing urban freeway with 4 lanes in each direction has the following characteristics.
Traffic data:
Peak hour volume (in the peak direction):
Trucks:
PHF = 0.93
Geometric data:
Lane width:
Shoulder width:
Total ramp density:
Terrain: rolling
11 ft
6 ft
1.8 ramps per mile
Determine the LOS in the peak hour. (Assume commuter traffic and assume no RVs.)
LOS A
LOS B
LOS C
LOS D
LOS E
LOS F
mean speed
density
7,010 veh/h
10% of peak hour volume
Show the demand flow rate (in pc/h/In), mean speed (in mi/h), and density (in pc/mi/ln) for the given conditions.
demand flow rate
pc/h/In
mi/h
pc/mi/In
Chapter 9 Solutions
Traffic and Highway Engineering
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- An existing four-lane freeway in rural area is with the following :information Lane width 3.5m, 0.9m lateral clearance, 1800 veh/hr peak hour volume, PHF=0.9, interchange density =0.90, 5% trucks, 5% buses and the road is within a mountainous terrain. Then based on the HCM procedure, the service flow rate (pc/h/In) isarrow_forwardA freeway is to be designed to provide LOS C for the following conditions: design hourly volume of 5600 veh/h; PHF: 0.92; trucks: 6%; free flow speed: 70 mi/h; no lateral obstructions;rolling terrain; total ramp density of 0.75 ramps per mile.Determine: whether eight (four in each direction) 12 ft lanesare enough to provide LOS C.arrow_forwardA basic segment of a rural freeway has the following characteristics: • Four-lanes (two lanes in each direction)%3B There is one ramp within 3 miles upstream, and 2 ramps within 3 miles downstream; 10-ft lanes; Right shoulder width of 4 ft; • Level terrain;. 10% trucks and 5% buses in the vehicle stream. Calculate the FFS at this freeway section and then determine the level of service (LOS) when the flow rate is 1740 pc/h/In. (Write the answer for the LOS in the box below).arrow_forward
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