A Toll Pricing Framework for Traffic Assignment Problems with Elastic Demand

This paper extends the notion of toll pricing and the toll pricing framework previously developed for fixed demand traffic assignment [4, 13] to the problem with elastic demand. The system problem maximizes net benefit to the network users [9, 20] and the user problem is the usual one of finding equilibrium with elastic demand. We define and characterize T , the set of all tolls for the user problem that achieve the system optimal solution. When solutions to the two problems are unique, T is a polyhedron defined by the optimal solution of the system problem, similar to the case in [4, 13]. The Toll Pricing Framework in [13] is also extended to allow optimization of secondary criteria over T . Examples include minimizing the number of toll booths and minimizing the maximum toll on any link. A numerical example illustrates the results.