高速车随机延迟逐步加速交通流元胞自动机模型

提出介于Nagel-Schreckenberg(NS)模型和Fukui-Ishibashi(FI)模型之间的一种新的一维交通流元胞自动机模型. 此模型采用NS模型中的车辆逐步加速方式,和FI模型中的仅最大速车可随机减速的车辆延迟方式.证明新模型的基本图,即车流渐近稳态的平均速度与道路上的车辆密度之间的函数关系与FI模型的完全相同.这也就是说,只允许最高速车辆可发生延迟的FI交通流模型,如果将其突然无限制加速方式(车辆可在一个时步内从零速加速到最高速限M或车头距离所允许的最大速度),改变为车辆的逐步有限加速 关键词： 交通流 元胞自动机模型 相变基本图 Nagel-Schreckenberg模型 Fukui-Ishibashi模型

THE GRADUAL ACCELERATING TRAFFIC FLOW GELLULAR AUTOMATON MODEL IN WHICH ONLY HIG H SPEED CAR CAN BE DELAYED

A new traffic flow cellular automaton (CA) model situated between Nagel-Schrecke nberg (NS) type and Fukui-Ishibashi (FI) type is defined and studied. This new m odel adopes the gradual acceleration scenario for all cars as NS model and the s tochastic delay scenario for only the car with speed limit as FI model. It is pr oved that the fundamental diagram of the average traffic flow speed as the funct ion of the car density for the new model is exactly the same as for FI model. Th is means that if the acceleration scenario of the FI traffic flow model in which a car may increase in velocity rapidly from zero to the velocity limit M or the maximum velocity permitted by empty spacing ahead, is changed to a gradual way in which the velocity of a car may increase by only one unit at most in one time step, the asymptotic steady state behavior of traffic flow will not be changed by interaction between cars and the self-organization evolution of the traffic flow.