The Special Case of Public-Transport Accessibility

This chapter addresses how public transport plays a special role in accessibility. Like driving, biking, or walking, its first job is to provide the mobility that allows travelers to reach their destinations. However, public transport differs from other modes in its capacity to boost proximity indirectly; it can bring origins and destinations closer together to shape land-use development toward higher proximity. These proximity impacts operate at both local and regional scales. When public transport enables large and concentrated downtowns to thrive, or when it facilitates metropolitan compactness overall, it is supporting a regional accessibility benefit that accrues to transit users and nonusers alike. Public transport also differs from other modes in that measuring its accessibility involves a series of technical challenges that planners and public officials must confront when they seek to extend the accessibility shift to the transit context. The chapter then considers the special challenges of public-transport accessibility measurement and then demonstrates one application of such measurement: the assessment of bus versus rail transportation deployments for their respective contributions to metropolitan accessibility.