考虑出行者决策惯性的超级街区路网优化方法

Optimization of Road Networks with Superblocks Considering Travelers’Decision Inertia

合理开放部分超级街区有助于缓解城市交通拥堵状况,但已有研究大多将系统中出行者视为完全理性人,且优化目标多集中在系统通行效率方面,较少考虑空气污染和交通安全问题,这与实际需求不符。为此,本文在考虑出行者出行决策惯性的基础上,兼顾街区用户感受,提出基于双层规划模型的超级街区路网优化方法。首先,将出行者分为城市出行者和街区内部出行者,构建考虑出行者决策惯性的混合用户均衡模型,探讨街区开放对其出行决策的影响,此为下层模型;其次,综合考虑出行成本、尾气排放、潜在交通安全隐患等因素,构建系统总成本最小的优化模型,此为上层模型。算例结果表明,开放超级街区能有效缓解城市交通压力,使得外部路段出行时间下降10.53%,但也使街区内尾气污染排放量增加1611 g/h,潜在交通事故数增加4.67起/年。分析发现,街区内部出行需求较低(内部路段平均饱和度小于0.6),且城市过境出行需求较高(街区外部路段平均饱和度大于0.72小于1.07)时适宜开放街区,其他情形下开放街区或无必要或严重影响街区内部出行。此外,出行者决策惯性越高,开放街区政策可应对的内外部出行需求也越高,即政策的适应性越强。本文构建的模型及分析结果可为决策者与管理者在制定城市街区规划政策、管理城市道路时提供理论支撑。

Opening superblocks can relieve the traffic congestion of urban road networks.Existing research regards travelers as completely rational individuals and focuses on the optimization of traffic efficiency,which is unrealistic.Therefore,a bi-level programming model is developed in this study to optimize road networks with superblocks while considering individuals’travel decision inertia and the feelings of residents in superblocks.First,individuals are classified into urban and intra block travelers,and a mixed user equilibrium model that considers travelers’decision inertia is established to address the route choice problem when the superblock is open,which is regarded as a lower level problem.Subsequently,an optimization model with the minimum total cost(including generalized travel,air pollution,and potential traffic accident costs)is constructed to solve the upper level problem.The results show that opening the superblock can effectively alleviate the urban traffic pressure and decrease the travel time of the external road network by 10.53%.Meanwhile,it increases the exhaust emission by 1611 g/h and the number of potential traffic accidents by 4.67 cases/year in the superblock.It is discovered that when the internal travel demand is relatively low(the average saturation of internal sections is lower than 0.6)and the external travel demand is relatively high(the average saturation of external road sections is between 0.72 and 1.07),the superblock should be opened.Otherwise,opening the superblock is unnecessary,or severe internal traffic congestion will occur and affect residents’daily life.Additionally,when the decision inertia of travelers increases,the internal and external travel demands that can be managed via the open block policy increase accordingly,which demonstrates the adaptiveness of the higher policy.The model and analysis results presented herein can provide theoretical support for decision makers and managers in formulating urban block planning policies and managing urban roads.