高速公路合流区上匝道混合车流通行能力经验计算法

Empirical Capacity Calculating Method for Expressway On-ramp Mixed Traffic Flow

研究高速公路合流区上匝道混合车流的通行能力的计算问题。利用已有的高速公路合流区外侧车道交通特征分析结论,推求在外侧车流不同车头时距分布特征下的上匝道混合车流汇合概率模型。运用回归技术和统计方法,建立了加速车道合流点分布概率的实测经验模型。对可接受间隙理论的原型进行了形式上的修正,最终建立高速公路合流区上匝道的混合车流通行能力经验模型,它是主路交通量、匝道交通量、加速车道长度、匝道混合车流比例以及各自的临界间隙和随车时距的函数。最后结合实例介绍经验模型的数值积分求解方法,并证实该经验计算方法具有较高的实效性和可操作性。

The capacity calculating method for expressway on-ramp mixed traffic flow was analyzed in this paper.Different merging models of mixed traffic flow on conditions of different superior flow headways were advanced according to existing analyzed conclusions conceming the on-ramp traffic characteristic. The empirical distributing probability model of merging spots was set up by using regression techniques and statistical methods. Finally, some modifications to gap acceptance theory model were made and the empirical highway capacity model of the on-ramp mixed traffic flow, which is a function of flow rate, the length of acceleration lane, respective proportions of mixed traffic critical gap and following time of mixed traffic flow, was founded. In the end, the numerical calculating method was demonstrated by an example and some fieldwork data proved that the model has good practicability and maneuverability.