车头时距混合分布模型  

Mixed Distribution Model of Vehicle Headway

作　　者：陶鹏飞[1] 王殿海[1,2] 金盛[2] 

机构地区：[1]吉林大学交通学院,吉林长春130022 [2]浙江大学建筑工程学院,浙江杭州310058

出　　处：《西南交通大学学报》2011年第4期633-637,644,共6页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金资助项目(70971053)

摘　　要：为描述车头时距分布特性,基于二分车头时距的基本思想,将行驶车辆状态分为跟驰状态和自由流状态,在分析其运行特征的基础上,建立了能同时描述这两类状态对应的车头时距分布特性的混合分布模型.应用实测数据,通过EM(expectation maximization)算法确定模型的相关参数,并结合参数取值分析了路段上、下游和不同车道内车辆行驶统计特征的差异性,最后,进行了实例验证.研究结果表明:混合分布模型在实验路段各处均可通过卡方检验;与负指数分布、爱尔朗分布和M3分布相比,混合分布模型对车头时距分布情况的拟合精度平均提高10%以上,且对快速路入口匝道通行能力的计算结果与实测值较为接近.For describing the distribution characteristics of headway,driving behaviors are classified into car-following state and free driving state by reference to the two-fluid theory.After analysis of their operation features,a mixed distribution model that can describe the headway distribution of both the two driving states was built.The model parameters were determined by expectation maximization（EM） algorithm using the measured data.Then,the differences between the statistical characteristics of the driving behaviors in up-stream section,downstream section and different lanes were analyzed and verified through a case study.The results show that the mixed distribution model can pass the chi-square test in all road situations.Compared with the negative exponential distribution,Erlang distribution,and M3 distribution,the mixed distribution model can improve the fitting accuracy of simulation by more than 10%,and obtain a more close result to the measured data in calculating the traffic capacity of an expressway on-ramp.

关 键 词：车头时距 分布模型 跟驰 自由流状态 

分 类 号：U491[交通运输工程—交通运输规划与管理]