[Apr 10] Xiaolei WANG: Design and Implementation of Tradable Congestion Credit for Network Mobility Management

In face of urgent traffic congestion problem around the world and consistent public resistance to congestion pricing, Yang and Wang (2011) recently proposed an alternative to road pricing―tradable credit scheme. Under a tradable credit scheme, the social planner initially distributes a number of credits to all eligible travelers at the beginning of each time period (e.g.one month or one quarter). Travelers then use these credits as a payment for the privilege to drive on any link of the network, but the amount of credits to be charged by the planner from road users is link-specific. To enhance economic efficiency, credits are allowed to be traded freely among travelers. Such credit trading can be performed at either online trading platform or offline trading stores. The government is in charge of monitoring the market, but is not allowed to enter the market as a buyer or seller. Meanwhile, on-road credit charging will be exercised through electronic system, like the existing Electronic Road Pricing (ERP) system which is composed of vehicle presence detectors and in-vehicle units. Given a tradable credit scheme, the user equilibrium (UE) and market equilibrium (ME) conditions with heterogeneous users are formulated into a variational inequalities (VI) problem. Sufficient conditions for uniqueness of the aggregate UE link flows and then the ME credit price are established. Appropriate tradable credit schemes are developed to decentralize system optimal and Pareto-improving network flow patterns.