Question

An urban circumferential freeway is to be designed on the basis of the following information: design year average annual daily traffic, AADT = 75,000 veh/day; the estimate of the percent of traffic occurring during the peak-hour is 9%; the percent of peak-hour traffic in the heavier direction is estimated to be 55%. The traffic mixture is expected to be similar to the current mixture of 7% trucks, 3% buses and no recreational vehicles. The PHF is estimated to be 0.9. The base free-flow speed is 70 mph. If the freeway is to be built on rolling terrain with no lateral obstructions and 12-ft lanes, determine the number of lanes needed to provide a minimum LOS of B.

Answer 1