一种新的混合车流下的元胞自动机交通流模型

在我国高等级公路上的车流主要是混合车流,而一般的交通流理论都是以小车流为对象进行研究和建模的。元胞自动机模型可以比较好地模拟交通流,新建立的混合车流下的元胞自动机交通流模型,除不同车型的车速上限不同外,而且车辆运行中所占元胞格点数也不同。通过计算机对新模型进行模拟,发现纯小车流、将大车按线形换算成小车流与混合车流的车流运行状态不尽相同,而且在车速方面差别更大。只要在车流中存在大车,整个车流的速度就会受到较大的影响,但车流密度较低时,车型比例对车速的影响又不是很明显,但平均速度低于大车的最大速度。另外,本模型为进一步更好地描述混合车流奠定了基础。

New Cellular Automaton Traffic Model with Mixed Traffic Flow

Mixed traffic flow is the basic characteristic of traffic flows of highways in China.But most theories and models about traffic flow were based on small cars.Cellular automaton(CA)model may mimic small-car flow accurately.A new traffic CA model with mixed traffic flow was proposed,which limits maximal velocities to different vehicle's types and advises that they occupy different number of cells at every time step.Some simulations were carried out and the results show that there are different in vehicle moving status,especially in vehicular velocity,between mixed traffic flow,small-car flow and non-mixed traffic flow by linearly transferring mixed traffic flow into small-car flow.And only if one large vehicle was in traffic flow,the velocity of the whole traffic flow would be greatly impacted,but under low density of traffic flow,the mixed ratio of traffic flow has slight influence on its velocity,while average velocity of traffic flow is slower than large-vehicle's maximal velocity.This model also makes a platform for studying mixed traffic flow in detail for the future.