高速公路合流区车辆换算系数研究

车辆换算系数是道路通行能力研究的重要组成部分，合流区内的车辆运行特性与基本路段有着显著差异，其车辆换算系数也应和基本路段有所差异。通过对实测交通流数据的处理分析，以车辆瞬时占用道路时间和车身长度为指标进行聚类，将高速公路合流区车型划分为4种，进一步计算了4种车型之间所形成的16种车头时距，并以车头时距为基础推导了车辆换算系数的计算模型，根据实测数据计算得出了高速公路合流区各车型车辆换算系数。采用饱和车头时距法和流量车速法分别对得到的车辆换算系数进行了验证，结果表明，计算的车辆换算系数具有一定的实用性。

Passenger Car Equivalence in Freeway Merging Area

Passenger car equivalence （PCE）is an important part of capacity study. The traffic characteristics of vehicles in merging-area are remarkably different from those in basic sections. Based on the analyzing the measured traffic flow data, vehicle types were classified into 4 kinds according to the index clustering of vehicle instantaneous velocity and vehicle body length. The 16 kinds of headway between the four kinds of models were calculated. Based on the calculating capacity by means of time headway, an algorithm for PCE was derived. Moreover, the recommended merging area PCE value was obtained from measured data. Standard passenger car capacity and mixed vehicle capacity in merging area were calculated respectively by using saturated time headway method and flow-velocity method. Finally, the PCE obtained in this paper is validated according to the standard passenger car capacity. Results show that the PCE calculated has a certain practicality.