基于一维元胞自动机的可变时距跟车模型

Variable time-headway car following model based on one-dimensional cellular automaton

依据不间断车流的车头时距分布规律和一维元胞自动机建模理论,提出了一种可变时距跟车模型.该模型假定行驶车辆都趋向于保持一个期望的车头时距,通过对前车速度和车头间距的估计,并考虑随机减速的影响对车速进行同步更新.基于该模型建立的仿真系统,凭借两个简单的参数来调节不同车速的期望车头间距,使车头时距分布规律符合交通未饱和时车头时距的具体分布情况,从而能够描述多车道公路上比较复杂的交通状况,表示不同道路等级的通行能力.

A variable time-headway car following model was presented based on time-headway distributing rule in actual traffic and one-dimensional cellular automaton modeling theory. The model assumes that every vehicle tends to keep expected time-headway and each vehicle synchronously updates its velocity by estimating the velocity of the head vehicle, the distance-headway and the probability of random slowdown. The time-headway distribution of the simulation system based on this model can be tuned by two simple parameters, so it can accord with different time-headway distribution rule in condition of practical unsaturated traffic. Thus the simulation system based on the model can describe rather complicated traffic states on multi-lanes highway and indicate traffic capacity of different highway grade.