非合作交通网络中的Braess悖论及其避免

平衡交通流网络中存在一种看似矛盾的Braess悖论现象,即在交通网络中增加一条通路反而会降低网络性能。本文分析了悖论产生的机理,指出Braess悖论的出现是由于非合作网络中Nash平衡点不在Pareto边界上,并通过实例分析说明交通规划时应该尽量避免设计出可能导致Braess悖论发生的路网结构,而对于现有交通网络中存在的Pareto悖论现象,可以通过控制和诱导等策略使交通流的分配达到Pareto最优,从而避免悖论发生。

Characterizing and Avoiding Braess's Paradox for Traffic Networks

Braess illustrated an apparently paradoxical situation in equilibrium traffic flow in which adding a new link to traffic network results in increased equilibrium travel cost for all travelers.Analyzing a simple network with Braess Paradox,we state that it occurs when the Nash equilibrium is not Pareto optimal.When traffic planning,the structure probably leading to Braess Paradox should be avoided.While for the existing road network,traffic control and guidance is used to assign the traffic flow to reach Pareto Optimum in order to avoid Braess Paradox.