A train stopping for longer than timetabled at a station is a common cause of service delay. Most of these delays are less than three minutes. They are ‘sub-threshold’, meaning they do not go through the delay attribution process. But even delays of tens of seconds can, when aggregated, adversely impact the overall performance and capacity of the network. 

Measures introduced because of Covid-19, such as social distancing and more frequent timetable changes, mean that the industry is facing new operational challenges. A better understanding of the root causes of dwell delay and the steps that can be taken to mitigate its impact will play an important role in ensuring punctual and reliable services for customers.