A schedule-based timetable model for congested transit networks

Abstract

This study proposes a model and method for solving the transit timetabling problem with consideration of passenger path choices within a congested and schedule-based transit network. The model has two submodels: transit timetabling and passenger-equilibrium assignment. The transit timetabling submodel generates timetables to improve passengers’ journey experience based on the results of passenger-equilibrium assignment, whereas the passenger-equilibrium assignment loads passengers on transit vehicles based on a fixed vehicle capacity and timetable output from the transit timetabling. An iterative method is developed to connect these two submodels and efficiently determine an optimal solution. The iterative method includes an equilibrium assignment method to simulate passenger loading and suggests a decomposition approach for transit timetabling. The decomposition approach has a significant computational advantage when handling transit systems that involve hundreds of transit vehicles because the algorithm generates a timetable for one transit line in each step rather than for all transit lines. The decomposition approach can therefore handle relatively large problems with more transit lines. The suggested algorithms are analyzed with a hypothetical example and with the practically sized example of South China’s high-speed railway in terms of efficiency, optimality, and applicability.