Risk-Based Transit Schedule Design for a Fixed Route from the View of Equity

Abstract

This work proposed a model for transit schedule design by integrating the spatial-equity considerations into the slack-time setting problem. The proposed model can help to design a transit service for more equitable reliability of all stops distributed along the route. The transit operators’ risk taking attitudes are also taken into consideration by introducing the travel-time budget (TTB) and mean-excess travel time (METT) as two risk measures. The proposed model can be formulated as a stochastic optimization problem and solved by a subsequently designed Monte Carlo (MC) simulation based genetic algorithm (GA) procedure. Scenario-based numerical examples from a real bus route in Beijing city of China are presented to demonstrate the characteristics of the model. The sensitivity of the parameters setting are also taken into consideration as well, which reflects the impact on the schedule setting of various factors including actual travel-time variability, risk-taking attitudes of transit operators, the bus drivers’ adjustment, and bus-frequency setting.