基于VISSIM仿真的山区高等级公路雾区限速方法

摘要

针对目前山区高等级公路雾区限速理论不能切实反映雾区交通流状态的情况,在完善雾区限速理论的同时,提出了具体的限速方法.首先建立不同大气能见度下驾驶员动态可视距离与车速的关系模型;并以驾驶员的动态可视距离不小于停车视距为条件,得到不同雾况等级下的限速值;其次,考虑到雾区交通量对限速值的影响,基于流量-速度模型,对同一雾况等级根据交通量的大小分级限速;最后,以限速值为变量进行VISSIM仿真对比试验,将车速方差和安全车距达标率作为评价限速值优劣的指标,对雾区限速理论值进行优化;该方法适用于不同交通流状态,可为山区高等级公路雾区交通安全保障方案的制定提供参考.%Aiming at the present speed limit theory of mountain high-grade highway in fog area can not reflect the traffic state,the specific speed limit method is put forward while perfecting the theory in fog area.Firstly, the model between dynamic visual distance and speed is established at different atmospheric visibility, and the speed limit value at different levels of fog area is drew according to the dynamic visual distance of drivers is not less than the stopping sight distance.Secondly, taking into account the effect of traffic volume, the speed limit is graded at the same level according to traffic volume based on the traffic-speed model.Finally, taking the speed limit value as the variable, the VISSIM simulation comparison test is carried out which the speed variance and the compliance rate of safety car distance are regarded as evaluation indexes to optimize the speed limit value.The proposed method is applicable for different traffic flow and provide a reference for the development of traffic safety enhancement of mountain high-grade highway in fog area.