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 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.

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter9: Capacity And Level Of Service For Highway Segments

Section: Chapter Questions

Problem 8P

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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.
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 four-lane freeway (two lanes on each direction) is located on mountainous terrain with 11-ft lanes, a 5-ft right-side shoulder, and a 3-ft left-side shoulder, and a 60- mph design speed. The freeway currently operates at capacity during the peak hour. If an additional 11-ft lane is added, and all other factors stay the same, what will the new level of service be?
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 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?
A 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).
A 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.
A rural collector highway is to be constructed in an area of rolling terrain where the ADT is 950 veh/day. For this situation, determine the following design values: a. Minimum design speed b. Desirable lane width and shoulder width c. Maximum desirable grade
A 5% upgrade on a six-lane freeway (three lanes in each direction) is 1.25 mi long. On this segment of freeway, there is 3% SUTS and 7% TTs, and the peak-hour factor is 0.90. The lanes are 12 ft wide, there are no lateral obstructions within 6 ft of the roadway, and the total ramp density is 1.0 ramps per mile. What is the maximum directional peak-hour volume that can be accommodated without exceeding LOS C operating conditions in veh/h? Round of your answer to whole number. Blank 1
An eight-lane freeway section is designed to have a lane width of 12 ft, right-side shoulder width is 3 ft, and 3 ramps over a 2-mile-long centerline. What is the free-flow speed for this freeway section? a. 75 mph b. 70 mph 65 mph O d. 60 mph C.
(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.
Civil Engineering A four-lane rural freeway segment has a 510 m grade length of 2% upgrade followed by a 630 m grade length of 3%. The freeway has 3.4-m lane, 1.5m left-shoulder lateral clearances and interchanges spaced at every 25 km. During the peak hour, there are 6% trucks, 2% buses, 2% recreational vehicles and the rest are passenger cars. Driver population adjustment is determined to be 0.90, peak hour factor is 0.90 and the BFFS is 110 km/h. At present, the freeway operates at capacity during the peak hour in the direction in question. If an additional 3.4 m lane is introduced, and all other factors stay the same, what will be the new level of service?