冰雪条件下城市快速路限速研究

摘要

为了提高冰雪条件下城市快速路车辆行驶的安全性，通过视频录像和人工调查等方式获得哈尔滨市部分快速路在不同冰雪条件下的交通流基础数据，分析车流量、大小车型、车道位置等因素对运行速度的影响，并基于车辆追尾时的临界条件以及车辆的跟驰特性，建立与道路附着系数、交通量等参数相关的安全限速模型，并利用不同冰雪路面附着系数对模型中的路面参数进行标定，重点研究了冰雪环境对城市快速路车辆限速的影响，提出按交通量分级限速管理的方法。研究表明：冰雪条件下模型确定的限速值可以满足快速路上车辆的行驶安全；车辆在松雪、冰雪、冰膜路面上的限速值依次降低，在除雪作业后，限速值可以提高10~20 km/h；城市快速路在冰雪条件下的限速值需分车道分车型进行设置，相邻车道大、小型车限速值相差5~10 km/h；冰雪条件下的限速应根据交通量小于800 pcu/h、800~1500 pcu/h、大于1500 pcu/h 采用分级限速管理措施，以提高快速路的运输效率。%In order to improve traffic safety on urban expressways under the ice and snow,the effects of traffic vol-umes,vehicle types and lane positions on vehicle speed are investigated,where traffic flow data is collected from video re-cording and manual investigation in expressways in Harbin.Based on the characteristics of the critical condition of vehicle rear-end collision and vehicle-following,a speed limit model is developed,including variables of the road friction coeffi-cients and traffic volume,etc.The parameters of this model are calibrated using the surface friction coefficients under dif-ferent conditions of ice and snow,and the focus is to study the effects of ice and snow on the speed limit of urban express-ways.Finally,a method for optimizing speed limits by traffic volume levels is proposed.The study results showed that the speed limits determined by the proposed model could meet the requirements of vehicle safety on urban expressways under the condition of ice and snow.The speed limit is getting lower in a descending order of snow,ice,and ice film,but it can be increased by 10~20 km/h after the snow is cleaned.The speed limits for individual lanes and different types of vehicles should be set up differently on urban expressways under the ice and snow conditions,and the differences of speed limits between adjacent lanes should be within 5~10 km/h as well as between small and large vehicles.The speed limits should be set up according to different levels of traffic volumes under ice and snow conditions,including less than 800 pcu/h,800~1 500 pcu/h,and more than 1 500 pcu/h,which will increase the efficiency of transportation systems.