Equitable Traffic Assignment with Environmental Cost Functions

Abstract

In the past 10 years increased importance has been placed on public participation and environmental concerns in transportation system decision-making. While there are numerous societal objectives to consider when planning and operating a transportation system, it is not clear whether the optimal strategy with respect to one objective is also the optimal strategy with respect to the other objectives. This paper examines how new objectives and environmental considerations can be modeled within the traditional, macroscopic traffic assignment methodology. In addition, a new methodology for modeling the assignment of vehicles in realistic networks is developed based on equitable, rather than user-equilibrium or system-optimal, principles. The basic premise is that with the advent of intelligent transportation systems (ITS) the operation of the transportation system based on the objectives of the general public, rather than the traveling public and system operators, is feasible. A methodology for modeling these situations is required. All of the approaches discussed here were tested on a calibrated network from Edmonton, Alberta, Canada.