考虑用户紧急程度的在途路径诱导策略研究

Study on En-route Route Guidance Strategy Considering User’s Urgency Degree

为了提高突发交通拥堵情境下在途路径诱导效率,从用户体验层面出发,对诱导方案设计进行深入研究。提高用户体验有利于提高用户对诱导系统的服从率,从而提高诱导效率。道路拥堵状况是影响用户体验的重要因素,考虑到具有不同紧急程度的用户对拥堵感知存在差异,以感知拥堵作为路径诱导中路径分配的限制因素。首先构建衡量用户紧急程度的紧急函数,在此基础上设计行驶时间感知效用算法,然后将其作为干预项加入到随机均衡备选路线分配模型中,突发交通拥堵出现时,系统根据构建的备选路线分配模型递归地为突发事件L距离内的用户指派行驶路线。同时考虑到突发拥堵下交通状态具有较强的波动性,采用时变路网下的改进A~*算法计算路径分配方案的最短路径,其中,将预测的路段平均速度与历史平均回归模型结合计算行程时间,并将其作为A~*算法估价函数中的评估函数,从而实现考虑时间依赖性的实时最短路径寻优。最后,以秦皇岛海港区部分路网区域为例,利用微观仿真软件SUMO分别从诱导服从率、诱导效率、诱导时效性3方面对在途诱导方案的有效性进行仿真验证,并与现有的典型路径诱导方案进行对比分析,结果表明所提出的在途路径诱导策略可以改善突发拥堵下的交通状况。

In order to improve the en-route route guidance efficiency under traffic emergency congestion, the design of route guidance scheme is deeply studied from the perspective of user experience. Improving user experience is conducive to improve user’s compliance with the route guidance system and improve the route guidance efficiency. Road congestion is an important factor which affects user’s experience. Considering that the users with different urgency degrees have perception differences of congestion, the perceived congestion is taken as the limiting factor of route allocation in route guidance. First, an emergency function for measuring the emergency degree of users is built. On this basis, an algorithm of travel time sensing utility is designed, which is used as an intervention item in the stochastic equilibrium substitutive routes allocation model. When traffic emergency congestion occurs, the route guidance system recursively assigns driving routes to users within the L distance of the emergency by the model. At the same time, considering the strong fluctuation of traffic state in the case of emergency congestion, improved A~* algorithm under the time-varying network is used to calculate the shortest path of the path allocation scheme. Among them, the predicted average section speed is combined with the historical average regression model to calculate the travel time, which is taken as the evaluation function in the A~* algorithm evaluation function, so as to realize the real-time shortest path optimization considering traffic time dependence. Finally, taking partial road network region of Qinhuangdao Harbour area for example, the simulation experiments are carried out to verify the effectiveness of the en-route guidance strategy from the aspects of guidance compliance rate, guidance efficiency and guidance time-effectiveness by the micro-simulation software SUMO, and the strategy is compared with the existing typical route guidance schemes. The result shows that the proposed en-route route guidance strategy could improve the traffic condition under emergency congestion.