28-7 A long segment of suburban freeway is to be designed on level terrain. The level segment, however, is followed by a 4.5% grade, 2.0 miles in length. If the DDHV is 2,500 veh/h with 15% trucks (standard mix), how many lanes will be needed on the (a) upgrade, (b) downgrade, (c) level terrain segment to provide for level of service C? Lane widths and lateral clearances may be assumed to be 12 ft and 6 ft, respectively. Ramp density is expected to be 1.0 ramps/mi. The PHF is 0.92. Good weather, no incidents, no work zones, and regular users of the facility may be assumed.

28-7 A long segment of suburban freeway is to be designed on level terrain. The level segment, however, is followed by a 4.5% grade, 2.0 miles in length. If the DDHV is 2,500 veh/h with 15% trucks (standard mix), how many lanes will be needed on the (a) upgrade, (b) downgrade, (c) level terrain segment to provide for level of service C? Lane widths and lateral clearances may be assumed to be 12 ft and 6 ft, respectively. Ramp density is expected to be 1.0 ramps/mi. The PHF is 0.92. Good weather, no incidents, no work zones, and regular users of the facility may be assumed.

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter15: Geometric Design Of Highway Facilities

Section: Chapter Questions

Problem 2P

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A long segment of suburban freeway is to be designed on level terrain. The level segment, however, is followed by a 4.5% grade, 2.0 miles in length. If the DDHV is 2,500 vehicles per hour with 15% trucks (standard mix), how many lanes will be needed on the (A.) Upgrade, (B.) Downgrade, (C.) Level terrain segment to provide for level of service C? Lane widths and lateral clearances may be assumed to be 12 feet and 6 feet, respectively. Ramp density is expected to be 1.0 ramps per mile. The PHF is 0.92. Good weather, no incidents, no work zones, and regular users of the facility may be assumed.
A 5% upgrade on a six-lane freeway (three lanes in each direction) is 1.25 mi long. On this segment of freeway, the directional peak-hour volume is 3800 vehicles with 2% large trucks and 4% buses (no recreational vehicles), the peak- hour factor is 0.90, and all drivers are regular users. The lanes are 12 ft wide, there are no lateral obstructions within 10 ft of the roadway, and the total ramp density is 1.0 ramps per mile. A bus strike will eliminate all bus traffic, but it is estimated that for each bus removed from the roadway, seven additional passenger cars will be added as travelers seek other means of travel. a.) What is density, before the bus strike? b.) What is the volume-to-capacity ratio, before the bus strike? c.) What is the level of service of the upgrade segment before the bus strike? d.) What is density, after the bus strike? e.) What is the volume-to-capacity ratio, after the bus strike? f.) What is the level of service of the upgrade segment after the bus strike?
A new basic freeway segment will have 3 lanes in each direction. The left and center lane each has a width of 12 ft while the width of the right lane is 13 ft. The left shoulder is 4 ft while the right shoulder is also 4 ft. There are 2 interchanges within 6 miles (3 miles upstream and 3 miles down stream).The site has level terrain, the design speed is 80 mph the hourly design volume is 5250 veh/h, which includes 9.0% trucks and buses. The peak hour factor is 0.870. Calculate FHV, VP, FFS, LOS Show all work
Find the upgrade and downgrade service flow rates and service volumes for an eight lane freeway with the following characteristics: (11 ft lanes, 2 ft right-side clearance, 4.2 ramps/mile, 3% trucks, good weather, regular drivers, PHF of 0.92) The segment in question is on a sustained grade of 3.5%, 1.5 miles in length.
(a) A six-lane freeway (three lanes in each direction) has regular weekday users and currently operates at maximum LOS C conditions. The lanes are 11 ft wide, the right-side shoulder is 4 ft wide, and there are two ramps within three miles upstream of the segment midpoint and one ramp within three miles downstream of the segment midpoint. The highway is on rollingterrain with 10% large trucks and buses (no recreational vehicles), and the peak-hour factor is 0.90. Determine the hourly volume for these conditions.
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A four-lane basic freeway segment on level terrain is being redesigned. The current roadway has 12 ft lanes with 4 ft shoulders. The proposed alignment would expand to six 11-ft lanes with 2 ft shoulders. The road carries 3000 vehicles in the peak hour in one direction, with 925 coming in the peak 15 minutes. The truck mix is 70/30 and makes up 10% of traffic. What is the density and LOS (level of service) before and after the proposed change?
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QUESTION 1 A four-lane urban freeway segment has a peak demand volume of 3,500 vehicles per hour for the two eastbound lanes. The PHF is 0.95 and there are no trucks, buses or RVs because the freeway is classified as a parkway and such vehicles are prohibited. The segment has 12 ft lanes, no lateral obstructions, 3 ramps within the influence area, and meanders through some beautiful rolling terrain. Assuming the road will be used by commuters and those familiar with the road, what is the flow rate (pcphpl)? Provide your answer to the nearest integer.