Impacts of public transit delays and disruptions on equity seeking groups in Toronto – A time-expanded graph approach

This study employed graph theory techniques to evaluate the global efficiency of Toronto's transit network. Using global efficiency, which measures the ease with which riders could reach their destinations, we explored if disadvantaged riders suffered the same level of travel time delays as the general population during both minor (recurrent) service disturbances and major (non-recurrent) disruptions. We modified the global efficiency measure by applying weights representing origin-destination trip flows for six population groups of interest separately. We used a time-expanded graph, which we built using real-time data scraped from the public APIs of the Toronto Transit Commission. This approach allowed us to create travel time estimates that considered the effects of real-world headway performance on travel times over 16 days during the winter of 2019. Our analysis found that disadvantaged groups experienced similar reductions in global efficiency and similar increases in travel time during both routine delays and major transit disruptions compared to the general population. Groups with predominantly suburban travel patterns, such as Black and Low-Income riders, had slightly lower drops in global efficiency than the general population, showing their better resilience to delays and disruption.