Passenger Car Equivalence Research out of Level of Service Consideration

Taking equal effect on the velocity of cars as the equivalent criterion,Passenger Car Equivalents under different mixed traffic flow,mixed rate and velocity of trucks were obtained on the basis of microscope simulation and mathematic method.The result shows that the decreasing of truck velocity will cause sharp increase of Passenger Car Equivalent,and there is no need to study Passenger Car Equivalent when both the mixed traffic flow and mixed rate are low.When traffic flow is close to the capacity,Passenger Car Equivalent is chiefly determined by the truck size;When traffic flow is in between,Passenger Car Equivalent will increase with the increase of mixed traffic flow and mixed rate respectively at first and will decrease at last.Validation with the field data of Guang-Shao freeway shows that the result agrees well with the existed traffic situation in China.