基于密度熵的道路交通事故影响范围分区模型

考虑路径阻抗的动态变化, 定义了网络初始荷载; 以事故持续时间为变量, 采用前景理论确定了网络负载重分配的方式; 根据交通流密度熵构建了耗散结构模型, 并与负载分配过程相结合确定了各路段的交通流密度熵变化率; 构建了基于聚类分析的交通事故影响范围分区模型, 通过仿真试验探讨了不同初始荷载和事故持续时间对分区的影响。仿真结果表明: 在交通量基数为800 pcu·h-1时, 事故持续时间从20 min增加到30 min, 直接影响区有向路段由3个增加到6个, 间接影响区有向路段由5个增加到18个, 说明受事故影响路段的熵处于快速上升阶段, 路网的级联失效不明显; 随着交通量基数增加到1 000 pcu·h-1, 事故持续时间从20 min增加到30 min, 直接影响区有向路段由8个增加到19个, 间接影响区有向路段由16个增加到21个, 说明交通量对路网的影响主要集中在直接影响区。可见, 不同交通情况下, 各有向路段受到事故路段的影响程度明显不同, 随着事故持续时间与初始流量的加剧, 路网中有向路段的受影响程度均增大, 因此, 采用交通事故影响范围分区能够精细地描述道路运行状态的动态变化过程。 

Partition model of road traffic accident influence area based on density entropy

The initial load of network was identified based on the dynamic effect of path impedance. The duration of accident was considered as parameter, and the network load re-distribution was introduced based on the prospect theory. The dissipative structure model was established by the entropy of traffic flow density, and the change rate of traffic flow density entropy of each road was determined by combined with the load distribution process. The partition model of traffic accident influence area was established based on cluster analysis. The influence of partition was analyzed by simulation experiment under different initial loads and accident durations. Simulation result shows that when the traffic base is 800 pcu·h-1and the accident duration changes from 20 min to 30 min, the number of directed road sections in direct impact area increases from 3 to 6, and the number of directed road sections in indirect impact area increases from 5 to 18, indicating that the entropy of road section affected by accident is on an upward trend and the cascading failure of road network is not obvious. When the traffic base rises to 1 000 pcu·h-1 and the accident duration changes from 20 min to 30 min, the number of directed road sections in direct impact area increases from 8 to 19, and the number of directed road sections in indirect impact area increases from 16 to 21, indicating that the effect is concentrated on the direct impact area. Therefore, the influence degree of each directed road section affected by accident is obviously different under different traffic situations. With the increases of accident duration and initial traffic flow, the influence degree of accident on directed road sections increases. Therefore, the partition of traffic accident influence area can precisely describe the dynamic evolution process of road traffic performance.