城市交通网络中社会成本的优化上界

Upper Bound of Social Cost Optimization in Urban Traffic Networks

在固定需求的交通网络中,均衡状态下的网络流量可能不是社会最优的,为了进一步明确用户均衡与系统最优之间的关系,通过引入一个与均衡流量社会成本相关的量值,得到城市交通网络社会成本优化上界的计算公式。结果表明:均衡交通网络流量模式的社会成本最高为社会最优流量模式的两倍,也就是说通过有效的控制策略最多可以节约网络社会成本的一半。

Existing research shows that network traffic at equilibrium may not be socially optimal in traffic networks with fixed demands. In order to further clarify the relationship between user equilibrium and system optimum flow patterns, new formula for computing the upper bound of social cost optimization in urban traffic networks was derived through introducing an alternate quantity associated with the user social cost of equilibrium flow pattern. The results show that the social cost of the equilibrium is twice the cost of the social optimum at most ; hence the social cost of the network can be halved through an effective control strategy at most.