A Mixed Integer Linear Programming Model for Train Service Improvement

An optimal train schedule enables the railway system to serve maximal passengers with limited resources. However, inappropriate train services may cause a diversity of adverse impacts such as service delay and long waiting times. This study aims to improve train service with a new schedule compared to the existing train schedule. To develop an alternative train service with a schedule solution, a mixed integer linear programming model is developed. A comparison between the existing train service and an alternative service is conducted based on a subset railway network in New South Wales, Australia. Numerical results proved that the alternative train service outperforms the existing one with regard to delay time and train capacity.

I. Introduction

The railway system is an essential component of the multi-modal transportation system, which plays an important role in the movement of both goods and people [1]. Train services are planned meticulously, and the corresponding schedules are often published in advance. Scheduling, regardless of the domain, is a complex problem influenced by capacity, resource, demand, uncertainty, and many other constraints. Train scheduling reflects the compromises required due to the limited resources, such as track infrastructure, rolling stock (carriages) and crew. Further, the perspective of the scheduler influences the objective(s) to be optimised, which ultimately has an impact on the schedule.