Role of streetscape feature in pedestrian safety: A modified multi-level multiple membership model

Pedestrians are among the most vulnerable road users in urban transport systems. Studies have explored the effects of the built environment, traffic, and human characteristics on pedestrian crash risk. However, the majority of these studies have focused on the association between pedestrian safety and influencing factors at macroscopic spatial scales. The influences of micro-level factors, particularly streetscape features, on pedestrian safety are less studied due to the unavailability of high-resolution spatial data. In this study, the influences of streetscape features, in terms of the percentage of green view, sky view, road space, sidewalks, buildings, and traffic signs, on pedestrian crash frequency are evaluated using a computer vision approach and citywide street view imagery. Additionally, the influences of other micro-level factors, such as pedestrian network configuration and transport facilities, and macro-level factors, including land use and socio-demographics, are accounted for. Since data at different spatial scales are used, a modified multi-level multiple membership model is adopted to jointly estimate the influences of both micro- and macro-level factors on pedestrian safety, accounting for possible spatial dependence and between- and within-level correlations. Results indicate that pedestrian crash frequency increases with the presence of a bus stop or metro exit, the number of crosswalks, general and barrier-free walking accessibility, and the percentage of building view. In contrast, pedestrian crash frequency decreases with the presence of a footbridge or underpass and the percentage of green, sky, road space, sidewalk, and traffic sign views at the microscopic spatial scale. Furthermore, land use and population socioeconomics also significantly affect pedestrian safety. The findings should shed light on urban design and planning strategies that can enhance walkability without compromising pedestrian safety.