Based on the framework of method of successive averages(MSA), a modified stochastic user-equilibrium assignment algorithm was proposed, which can be used to calculate the passenger flow distribution of urban rail tran...Based on the framework of method of successive averages(MSA), a modified stochastic user-equilibrium assignment algorithm was proposed, which can be used to calculate the passenger flow distribution of urban rail transit(URT) under network operation. In order to describe the congestion's impact to passengers' route choices, a generalized cost function with in-vehicle congestion was set up. Building on the k-th shortest path algorithm, a method for generating choice set with time constraint was embedded, considering the characteristics of network operation. A simple but efficient route choice model, which was derived from travel surveys for URT passengers in China, was introduced to perform the stochastic network loading at each iteration in the algorithm. Initial tests on the URT network in Shanghai City show that the methodology, with rational calculation time, promises to compute more precisely the passenger flow distribution of URT under network operation, compared with those practical algorithms used in today's China.展开更多
基金Project(2007AA11Z236) supported by the National High Technology Research and Development Program of ChinaProject(2012M5209O1) supported by China Postdoctoral Science Foundation
文摘Based on the framework of method of successive averages(MSA), a modified stochastic user-equilibrium assignment algorithm was proposed, which can be used to calculate the passenger flow distribution of urban rail transit(URT) under network operation. In order to describe the congestion's impact to passengers' route choices, a generalized cost function with in-vehicle congestion was set up. Building on the k-th shortest path algorithm, a method for generating choice set with time constraint was embedded, considering the characteristics of network operation. A simple but efficient route choice model, which was derived from travel surveys for URT passengers in China, was introduced to perform the stochastic network loading at each iteration in the algorithm. Initial tests on the URT network in Shanghai City show that the methodology, with rational calculation time, promises to compute more precisely the passenger flow distribution of URT under network operation, compared with those practical algorithms used in today's China.
文摘为有效评价重大扰动事件下的路网性能,提出以日变交通配流(day-to-day traffic assignment,DTA)为基础的城市道路网络韧性评估模型.明确考虑重大扰动事件下交通流动态变化特性,构建了综合考虑出行者认知更新、行为惯性等因素影响的DTA模型,设计了启发式求解算法;定义了基于DTA的路网可达性指标,构建了可全面评价扰动事件生命周期内系统性能的韧性指标与评估模型,并在Nguyen&Dupuis网络上进行算例研究.结果表明:在扰动事件后的前10天,路网韧性波动变化,此后随着交通流分布趋于稳定,路网韧性单调上升,从第10天的0.323上升到第50天的0.794,上升了145.77%;与传统随机用户均衡(stochastic user equilibrium,SUE)模型相比,DTA模型获得的路网可达性与韧性指标存在显著差异,SUE模型下路网可达性随时间单调上升,而DTA模型下路网可达性在前15天剧烈波动,随后才单调增加,表明要获得准确的路网韧性指标,必须首先准确假定出行决策行为和相应配流模型;出行者行为惯性、路段通行能力退化程度与恢复速率以及路网拥挤程度等因素均对交通流量分布产生显著影响,进而影响路网可达性最终导致路网韧性指标发生显著变化,表明实际应用中应在充分调查的基础上合理标定相关参数.
