基于安全可靠性的多类用户交通分配模型

为探究出行安全对用户出行选择行为的影响，提出了考虑事故风险成本和旅行时间的多类用户交通分配模型。针对事故发生的随机性特征，定义了路径出行安全可靠性概念，并以此计算用户的事故风险成本预算，体现出行者的安全偏好。基于考虑事故机会和事故风险的基础事故预测模型，针对路段和交叉口的不同特征，分别定义了路段和交叉口的事故风险成本分布。构建的交叉口事故风险成本模型，体现了交叉口不同转向的事故风险成本的差异性。为了求解基于安全可靠性的多类用户交通分配模型，采用路径配流法和相继平均法设计了相应的求解算法，并通过算例分析了模型和算法的有效性。研究结果表明：安全可靠性在用户出行选择中具有重要影响。当在广义出行费用中考虑事故风险成本时，出行者会更多地选择事故风险成本较小的路径；不同风险倾向的用户会有不同的选择特征，保守型出行者倾向于选择路径事故风险成本标准差相对较小的路径，即事故风险成本波动小的路径，而中立型出行者倾向于选择事故风险成本均值相对较低的路径；考虑交叉口的事故风险成本与否会直接影响流量分配结果，即路径交叉口数量和转向的差异性同样会影响出行者的选择。所提出的模型对于客流预测和网络安全评价与管理具有潜在的应用价值。

Traffic Assignment Method for Multiclass Users Considering Safety Reliability

To explore the influence of travel safety on users' travel choice behavior, a traffic assignment model for multiclass users was proposed considering the crash risk cost and travel time. According to the randomness of the accident characteristic, the path safety reliability was defined, and the safety preference of the users was reflected by calculating crash risk cost budget herein. Based on the basic crash prediction model associated with crash exposure and crash risk, the crash risk cost distribution of road links and intersections were defined considering the different characteristics of links and intersections. Further, the difference in the turn crash risk cost was contained in crash risk distribution model of intersections. A path-based solution algorithm and a successive average method were designed to solve the traffic assignment model, and the validities of the model and algorithm were analyzed by the numerical example. The results show that the safety reliability has significant influence on the users' travel choices. Considering the crash risk cost in the generalized travel cost, users are more likely to choose the paths with lower crash risk cost. Specifically, users with different risk tendencies have different choice characteristics. Conservative users tend to choose the paths with smaller standard deviations in crash risk cost, namely the paths with lower fluctuations in crash risk cost. Meanwhile, neutral users prefer to choose the paths with lower mean crash risk costs. Moreover, considering the crash risk cost of intersections will directly affect the traffic assignment results. Namely, the number of intersections in a path and the difference in turn will also affect the users' choice. Additionally, the model also shows the potential application value for passenger-volume forecasting, as well as network security assessment and management.