ABSTRACT
This chapter studies transit network design with stochastic demand by considering two types of services-rapid transit services, such as rail, and fl exible services, such as dial-a-ride shuttles. Rapid transit services operate on fi xed routes and dedicated lanes, and with fi xed schedules, whereas dial-a-ride services can make use of the existing road network; hence are much more economical to implement. We integrate these two service networks into one multi-modal network and then determine the optimal combination of these two service types under user equilibrium (UE) fl ows. Two approaches are used to address the issue of stochastic demand: one is robust optimization; the other is stochastic programming. The robust optimization approach assumes that the stochastic demand is captured in a polyhedral uncertainty set. The UE principle is represented by a set of variational inequality (VI) constraints.
