考虑公交车辆影响的城市交通流元胞自动机模型

城市道路上的车流主要是公交车和小汽车混合流,而一般交通流理论都是以小汽车流为对象进行研究和建模。在对现有经典交通流元胞自动机模型进行总体分析的基础上,提出了一种考虑公交车辆影响的多速混合车辆双车道元胞自动机模型,重新标定了元胞长度、运行车速、随机慢化机制,引入了公交车辆,设定了公交车停靠站、改进了车辆变换车道规则,小汽车与公交车不仅最大速度不同,而且车辆运行中占用元胞点数也不同。通过计算机对新模型进行模拟,再现了传统交通流三参数之间的关系,发现纯小车流与考虑公交车流相比阻塞项更为明显和规律,只要在车流中存在公交车,整个车流的流量和速度就会受到较大的影响。为进一步更好地描述城市混合交通流奠定了基础。

New Cellular Automaton City Traffic Model Considering Public Transport Vehicles Affect with Mixed Traffic Flow

Traffic flow on city road is mainly composed of public transport vehicles and the car stream.But most theories and models about traffic flow were based on small cars.Cellular automaton(CA)model may simulate small-car flow accurately.Based on the NS models of traffic flow,a new traffic CA model with mixed traffic flow and consider the public transport vehicle in two-lane was proposed,which redemarcated the parameters,such as length of the cellar automaton,operation speed,random slow mechanism,and which not only set up bus station and improved vehicle changing lane regulation but also limited maximal velocities to different vehicle's types and advised that they occupied different number of cells at every time step.Some simulations were carried out and the results show that this model reproduced the relationship among three parameters of traditional traffic flow,and there are differences in vehicle moving status,especially in vehicular velocity and traffic rate of flow,and only if one public transport vehicle was in traffic flow,the velocity of the whole traffic flow would be greatly impacted.,This model also makes a platform for studying mixed traffic flow in detail for the future.