Sustainable Transportation Network Design with Stochastic Demands and Chance Constraints

This article proposes a new model for design of sustainable bi-modal transportation networks under demand uncertainty, with chance constraints on emission and equity issues. The proposed model is formulated as a bi-level programming problem. The lower level is a reliability-based traffic assignment problem for bi-modal transportation network, in which the transfer waiting time and non-linear bus fares are considered explicitly so that the passengers' behaviors on mode choice and path choice are simultaneously taken into account under demand uncertainty. The upper-level design objective is to maximize the network reserve capacity in terms of the summation of weighted mean and standard deviation of travel demands. A heuristic solution algorithm based on the particle swarm optimization method is adapted to solve the bi-level model. It is found in the numerical examples that both network reserve capacity and optimal design solution are substantially dependent on travel time reliabilities. It is shown that the proposed model can be used to assess the effects of various emission and demand equity constraints for sustainable development.