基于服务水平的车辆折算系数

Passenger Car Equivalence Research out of Level of Service Consideration

以对小客车的速度影响相同作为等效标准,利用微观仿真和数学建模的方法得到了不同混合车流量、货车速度和货车混入率的车辆折算系数.结果表明:货车速度的降低会带来车辆折算系数迅速增加;在流量和混入率都很小的时候,车辆折算系数没有实际意义;接近通行能力时,货车的影响主要与车辆尺寸有关;在中间状态,车辆折算系数最大,且分别随流量和混入率的增加先增后减.通过广韶高速公路上的数据验证表明,研究所得车辆折算系数能反应实际交通情况.

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.