During the peak hour, an urban freeway segment has a traffic flow of 6,000 veh/h, with 4,000 vehicles with one occupant and 2,000 vehicles with two occupants. The freeway has five lanes, four of which are unrestricted opening to all vehicles regardless of vehicle occupancy and one lane that is restricted for use by vehicles with two occupants. Link performance functions for the length of this freeway segment are tu = 30+ 0.5vu for the unrestricted lanes and tr = 20+2vr for the restricted lane, where t’s are in minutes and v’s are in 1,000 vehicles. Solve for the distribution of traffic among the lanes using the SO principle and compare the savings in person hours relative to a UE solution, assuming that the compliance is perfect and that no single-occupant vehicles use the restricted lanes.

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, 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

Consider the problem of traffic flow on a three-lane (one direction) freeway which can be described by the Greenshields model. One lane of the three lanes on a section of this freeway will have to be closed to undertake an emergency bridge repair that is expected to take several hours. It is estimated that the capacity at the work zone will be reduced by 30 percent of that of the section just upstream of the work zone. The mean free flow speed of the highway is 60 mi/h and the jam density is 130 veh/mi/ln. It is estimated that the demand flow on the highway during the emergency repairs is 86 percent of the capacity. Using the deterministic approach, determine the following for the expected repair periods of 1 h, 1.5 h, 2.5 h, 2.75 h, and 3 h. (a) the maximum queue length (in veh) that will be formed 1 h     veh1.5 h     veh2.5 h     veh2.75 h     veh3 h     veh (b) the total delay (in h) 1 h     h1.5 h     h2.5 h     h2.75 h     h3 h     h (c) the number of vehicles that will…