Question

Transportation Engineering

I. A highway transportation agency is conducting a traffic count on an existing highway for the purpose of determine the directional design volume. An automatic traffic counter using a weigh-in-motion (WIM) equipment gave a total continuous one-year count of 4,372,096 axles. Manual classification studies at the count station indicated the following: Passenger cars = 3-axle trucks 4-axle trucks 5-axle trucks = 69% 21% 6% 4% (a) Calculate the existing average annual daily traffic (AADT) in vehicles per day. Suppose that traffic on this roadway is expected to grow at annual rate of 1.8 percent for the next 10 years and that the city planners are planning to widen this suburban roadway in 10 years to accommodate this growth in traffic. What would be the forecasted AADT assuming vehicle classification proportions remain the same? What level of service (LOS) would you choose for design? What K and D factors would you choose for this roadway? What should be the directional design hourly volume (DDHV)? (b) (c) (d) (e)

Answer 1

Given that: - implies A high way trans portion agency is conducting a traffic count on an existing high way for the purpose of Determine. the directional design volume. rightarrow Manual classification studies at the count statue Indicated the following Passenger Cars = 69% 3-axle travels = 21% 4-axle travels = 6% 5-axle travels = 4% Given N = 4,372,096axles. Vehicle Damage factor. = (0.69 times 2.94 + 0.21 times 2.54 + 0.06 times 4.53 + 0.04*6.34) = 3.08. \r\n N = 365(VDF)A[(1 + r)^n-1]/r = r = 18% = 0.018 n = 10years. 4,372,096 = 365*3.08[A][1.018^10-1]/0.018 A = 358.43veh/day. Therefore implies The Average Annual daily traffic (AADT) In vehicles per day = 358.43veh/day. Implies That the city planners are planning to widdue this suburban roadway In 10 years to accommodate this growth In traffic.