Is It Too Crowded in Here?: In Search of Safety Standards for Pedestrian Congestion in Rail Stations

Many transit agencies have developed measurements of pedestrian crowding in rail stations but lack clear standards for when crowding becomes a safety risk that justifies an operating or capital intervention. How frequent, consistent, or severe must congestion be before a capital improvement is warranted to mitigate a safety risk? How should agencies weigh severe but infrequent congestion against moderate but daily congestion? Adoption of such standards is a critical step for a transit agency in identifying and prioritizing safety risks and capital needs. The Washington Metropolitan Area Transit Authority (WMATA, or Metro) uses a variety of methods to measure pedestrian crowding at Metrorail stations on platforms, escalators, and stairs and through fare gates. WMATA has incorporated big data into its measuring of crowding in rail stations and has recognized that using demand on a typical weekday can mask important variations and issues in normal operations. The agency has relied on the Transit Capacity Quality of Service Manual (TCQSM) to establish the capacity of station circulation elements, but the manual’s existing measures do not address questions of the frequency and severity of overcrowding or of what levels of crowding warrant action or capital projects. Although peer agencies commonly use station capacity values consistent with the TCQSM, other agencies have developed specific guidelines for acceptable peak crowding duration and special event conditions. This paper summarizes WMATA’s analytic approaches, including the use of pedestrian microsimulations to derive volume-to-capacity ratios and level of service. The paper concludes by calling for clear standards that consider frequency, severity, and acceptable safety thresholds.