博弈论视角下的交通分配系统最优与用户均衡的探讨

为了更好地解释系统最优与用户均衡两种交通分配方法间的定量关系,透过博弈论的视角,通过对算例的非合作博弈分析,从无限策略集下纯策略Nash均衡的角度指出了系统最优与用户均衡的统一性,二者作为Nash均衡的两种特殊状态,可以随博弈局中人数的变化而相互转化.同时,还对系统最优与用户均衡的转化过程进行分析,阐述其两阶段特征及对实际分配状态的影响,并通过在多场景中调整路阻函数的各项参数,指出路径的自由流走行时间作为＂初期优势＂,对转化速度和方向具有关键性影响.

Discussion of System Optimism and User Equilibrium in Traffic Assignment with the Perspective of Game Theory

In purpose of going deep into the quantitative relation between system optimism and user equilibrium,which are two classical methods of traffic assignment,the perspective of game theory is adopted.Through non-corporative game analysis to the example,it is showed that system optimism and user equilibrium can be integrated to pure strategy Nash equilibrium under infinite strategy sets.Exiting as two particular situations of Nash equilibrium,they can transform to each other with change of the number of game players.Furthermore,the transformation process between system optimism and user equilibrium is analyzed,which is characterized by two different stages.The impact that parameters in impedance functions exert on process is also researched,and it is argued that the free flow travel time,which reflects the original advantage of the route,has great influence on transformation speed and tendency.