在NaSch模型的基础上,分析车辆移动距离与车辆速度的关系,考虑驾驶的安全性,定义减速过程和位置更新规则,提出一种新的元胞自动机模型。该模型通过车辆前一步时的速度和当前速度计算车辆的移动距离。对该模型进行模拟仿真,得到车速、流量和密度数据及其相互关系,最大流量接近实测数据,显示了亚稳态、滞后效应、相分离以及同步流等更复杂的实际交通现象。仿真结果表明,车辆在行驶过程中能够相对均匀地分布在道路上,保持自由流状态,道路资源的利用率高,交通流量大,具有一定的合理性和实效性。
On the basis of the NaSch(NS)model,a one-dimensional Cellular Automaton(CA)traffic flow model is proposed,in which the relationship of vehicles moving distance and the vehicle speed is emphasized,the safety distance is considered,and the reduction process and location update rules are redefined. The model confirms current vehicle speed by vehicles moving distance and previous vehicle speed. By computer simulation,the relationships among speed,density and traffic volume are given to show the influence of moving distance on the traffic flow. The presence of metastable state,phase separation and hysteresis are revealed,which have been observed in real traffic. Simulation result shows that the model is reasonable and effective,and when the vehicle is on the road,its availability of road resources is high and traffic flow is big.