Safety of walking trips accessing to public transportation: A Bayesian spatial model in Hong Kong

The first mile and last mile (FMLM) problem is a prevalent and major problem faced by the government agencies and transport operators for the design, planning and management of urban public transportation. Among many other issues, it is rare that safety of access trips is assessed. Indeed, safe walking access is crucial for the promotion of walkability and sustainable transportation in a high density and transit-oriented city like Hong Kong. To evaluate the safety risk of car occupants including drivers and passengers of different transportation modes, comprehensive traffic count data are usually available to estimate the crash exposure. However, it may not be the case for the pedestrians accessing to different transportation modes. In this study, walking trip data from the household travel survey are used to estimate the pedestrian crash exposure accessing to different transportation modes at the macroscopic level. Then, a full Bayesian model with the conditional autoregressive (CAR) prior is established to measure the association between pedestrian crash frequency and possible influencing factors, with which the spatial correlation among neighboring areas is accounted for. Results indicate that numbers of walking trip accessing to buses, light buses and taxis are positively associated with pedestrian crash frequency. However, number of walking trip accessing to metro has no significant effect on pedestrian crash frequency. Additionally, built environment factors including land use and point of interest (e.g., hotels and restaurants), transport network characteristics (e.g., road length and number of metro exits), and socio-demographics including population age and ethnic group, all affect the pedestrian crash frequency. Such findings should shed light on the implementation of remedial measures including road design, traffic management and control, and planning of transport facilities that can improve the overall safety of pedestrian environment. Therefore, sustainable transport modes including walking and public transport can be promoted.