Traffic and Highway Engineering
5th Edition
ISBN: 9781305156241
Author: Garber, Nicholas J.
Publisher: Cengage Learning
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Question
Chapter 10, Problem 4P
To determine
The adjusted saturation flow rate for a lane group comprised of one lane for the through movement.
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Students have asked these similar questions
Determine the saturation flow rate (in veh/h) for a left-turn lane that operates in a permitted-only mode, under the following
conditions.
Opposing demand flow rate = 1,100 veh/h
Lane width 11.5 ft
Heavy vehicles = 4% of the traffic stream
Approach grade -6%
No on-street parking
No bus stops
Bicycle and pedestrian traffic conflicting with this lane group is negligible:
Intersection is not in a central business district
veh/h
A new section of a freeway is to be designed with a free-flow-speed of 65 mph along of
0.75 mile on 5% upgrade. The expected traffic volume is 4200 v/hr. The traffic composition
is 15% trucks, 5% recreational vehicles, and 10% buses. The peak hourly factor is 0.9, the
unfamiliar driver factor is 0.95. If the design requirement is to target a level of service (B),
how many lanes must be provided to satisfy the design requirement?
3.
Determine the LOS for pedestrians at two-phase signalised intersection with a cycle
length of 90 s. the phase serving the major street vehicular traffic gets 50s of green
whereas the phase serving the minor street vehicular traffic gets 30 s of green.
Useful formula:
dp
Table for assessing the LOS
LOS
A
B
C
D
E
F
0.5(C-g)²
C
Average delay/pedestrian (s)
>5
≥ 5-10
> 10-20
>20-30
≥ 30-45
> 45
Chapter 10 Solutions
Traffic and Highway Engineering
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.Similar questions
- A Four Lane freeway is located on rolling terrain with a free flow speed of 70 mph,12ft lanes, and no lateral obstructions within 8 ft of the pavement edges. the traffic stream consists of cars, buses and large trucks (no recreational vehicles) . A weekend directional peak hour volume of 1800 vehicles (*regular users*)is observed ,with 700 arriving in the mostly congested 15 minutes period . if a level of service no worse than C is required ,determine the maximum number of large trucks and buses that can be present in the peak hour traffic stream.. Dislike for wrong answersarrow_forwardA six-lane freeway (three lanes in each direction) in mountainous terrain has 10-ft lanes and obstructions 1 ft from the right edge. There are five ramps within three miles upstream of the segment midpoint and four ramps within three miles downstream of the segment midpoint. The traffic stream consists of mostly commuters with a peak hour factor of 0.84, peak-hour volume of 2500 vehicles, and 4% recreational vehicles. What is the level of service? (Write the letter only)arrow_forwardThe average normal flow of traffic on cross roads A and B during design period are 400 and 250 pcu per hour; the saturations flow values on these roads are estimated as 1250 and 1000 pcu per hour respectively. The all-red time required for pedestrian crossing is 12 secs. Design two phase traffic signal by Webster's method.arrow_forward
- Problem 2. Consider a freeway section with three lanes in each direction and with a length of 1.25mi (2km) and a +5% grade. In this freeway, the directional peak-hour volume is 3,800 veh/h, from which 76 are trucks and 152 are transit buses. The maximum 15-min volume within the hour of analysis is 1,055 vehicles. The lane widths are 12 ft (3.6m), and shoulder widths are 10 ft (3.1m). There are 2 exit ramps and 1 entrance ramp in the 3 miles in the upstream section and 1 exit ramp and 2 entrance ramp in the 3 miles in the downstream section (consider the same ramp density if using international (km) units). All transit buses will be removed from traffic since the transit service will be replaced by a commuter rail service. However, by removing buses, new additional passage car demand is expected. It is estimated that for each removed bus, 7 new passenger cars will be added to the original traffic volume of 3,800 veh/h. Question: Determine the change in speed and traffic density before…arrow_forwardA two-lane rural highway carries a peak hour volume of 465 (vph) and has the following characteristics: Roadway: 60mph design; 11 foot lanes, 2 foot shoulders; rolling terrain; 60% no-passing zones; length = 3 miles. Traffic: 70/30 directional split; 4% trucks; 2 percent recreational vehicles; 1 percent buses; PHF = 0.95 a) What Level of Service will the highway operate under during peak periods? b) What is the capacity of the highway? Explain why this is less than 2,800 (vph)?arrow_forwardA four-lane freeway with the following characteristics: ten foot travel lanes lateral obstructions at 0 feet at the roadside total ramp density is 4.5 ramps/mile rolling terrain The roadway has a current peak demand volume of 3500 veh/h. The peak hour factor is 0.95 and there are no trucks, buses, or RVs in the traffic stream because the roadway is classified as a parkway and such vehicles are prohibited. At what level of service will the freeway operate during its peak period of demand?arrow_forward
- Problem 2: A Class III two-lane highway is on level terrain, has a measured free-flow speed of 45 mi/h, and has 100% no-passing zones. During the peak hour, the analysis direction flow rate is 150 veh/h, the opposing direction flow rate is 100 vehh, and the PHF = 0.95. There are 5% large trucks and 10% recreational vehicles. Determine the level of service.arrow_forwardEight lane urban freeway is on level terrain with lane width of 12 ft, right shoulder lateral clearance of 4 ft, and 12 ramps over the 6-mi analysis segment. The traffic stream consists of unfamiliar road users. Peak hour volume for a directional weekday of 3200 vehicles is observed with 900 vehicles arriving in the most congested 15-min period. If the traffic stream has 20% large trucks and 20% buses and 15% recreational vehicles, determine the exact demand flow rate (in pc/h/In). Round your answer to 3 decimal places. Exclude the unit in the answer box.arrow_forwardEight lane urban freeway is on mountainous terrain with lane width of 12 ft, right shoulder lateral clearance of 4 ft, and 12 ramps over the 6-mi analysis segment. The traffic stream consists of familiar road users. Peak hour volume for a directional weekday of 5200 vehicles is observed with 500 vehicles arriving in the most congested 15-min period. If the traffic stream has 10% large trucks and 12% buses and 10% recreational vehicles, determine the heavy vehicle adjustment factor. Round your answer to 3 decimal places. Exclude the unit in the answer box.arrow_forward
- Example 5 A signalized intersection approach with no exclusive left- or right-turning lanes has a 35-second effective green out of a 60-second cycle. This approach has 4% of trucks and the approaching grade is 3%. Assume that the ideal saturation flow is 1,900 passenger vehs/h per lane. Determine the capacity of the intersection approach.arrow_forwardC] An urban freeway in an area with rolling terrain has 8 lanes (4 in one direction). It has 12-ft lanes and 4 ft shoulder clearance. The peak hour volume in peak direction is 6000 vph, with 8% trucks, and a peak hour factor of 0.90. On average there is one diamond interchange every 2 miles. Determine the following for the peak direction under study: (a). Passenger-car equivalent flow rate (pcphpl); (b). Estimated free-flow speed for prevailing conditions; (c). Average passenger car speed; (d). LOS.arrow_forwardA new section of Richmond Highway is being designed as a six-lane facility (three in each direction) with a two-way left-turn lane. Determine the peak-hour LOS. (Assume commuter traffic, 5% trucks, and no RVs.) Traffic data: demand volume = 3,120 veh/h PHF = 0.95 assumed base free-flow speed = 55 mi/h Geometric data: urban setting rolling terrain lane width = 11 ft shoulder widths = 4 ft (right side) and 1 ft (left side) average access point spacing = 12 points per mile on each side LOS A LOS B LOS C LOS D LOS E LOS Farrow_forward
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