Bi-Level Mathematical Programming Model for Locating Bus Stops and Optimizing Frequencies

Abstract

This paper proposes a model for locating bus stops and optimizing bus frequencies in congested local public transport networks. The analysis addresses the issue of reducing the overall costs of operating a transport system, including costs associated with provision of services and bus stop construction, using a bi-level mathematical programming method. The upper level defines the overall cost of the system, which must be kept to a minimum taking into account operational restrictions, and the lower level defines a behavioral model for system users. The suggested model mixes optimization and simulation and allows supply and demand to be linked; this ensures consistency between equilibrium flows and bus frequencies and between equilibrium flows and the distances between bus stops calculated at each iteration of the algorithm.