Reducing Delays on High-Density Railway Lines: London-Shenfield Case Study

This case study describes the development of a new timetable designed to reduce delays on the London-Shenfield regional railway line in the United Kingdom (UK). Reducing delays on high-density railway lines is challenging because frequent service makes it difficult to identify the root cause of delays and there is limited ability to solve delay problems by adding buffer times to timetables. On the other hand, it is very important to reduce delays on high-density lines since they affect many passengers and because a delay on one train can easily affect following trains. In this study, detailed railway operational data was used together with Oyster card ridership data to identify the root cause of delays and help develop an alternative timetable. The alternative timetable was tested and refined using stochastic simulation. The new timetable was placed in service during 2016 and led to a significant reduction in delays: punctuality within 5-min of scheduled arrival time increased by 6.2% during the most critical hour of the morning peak period. The paper describes the methodology, its application, study results, and transferability.