Understanding the roles of rail stations: Insights from network approaches in the London metropolitan area

In strategic transport planning, rail stations play different roles at different scales, particularly in large cities and metropolitan regions, where movement structure shows polycentric patterns. However, there is a general lack of evidence-based studies investigating the relative network roles of rail stations. Therefore, this paper aims to explore rail stations' roles within and beyond metropolitan communities in London. Drawing on the Transport for London's newly released NUMBAT passenger origin-destination data, we unravel the travel structure and identify the stations' roles through network methods, community detection and Z-P scores. Our research has three results: First, London's passenger movement network can be subdivided into seven communities. The majority of stations within the same communities are geographically localised with few exceptions. Second, stations play distinct roles in handling the patterns of movement at different scales. Typically, there exists a set of stations that are significant for connecting between metropolitan communities, because the disruption of those stations will have a greater impact on overall network efficiency and affect a larger and more diverse group of passengers. Third, a classification of rail stations is developed based on stations' commitment at two scales. This classification allows planners to have a finer level of understanding of the network role of the stations and thus develop and adjust tailored (re)development strategies.