Towards exposure-based time-space pedestrian crash analysis in facing the challenges of ageing societies in Asia

The global ageing phenomenon leads to major road safety concerns. This paper represents a pioneer but preliminary attempt to propose an exposure-based time-space approach to examine elderly pedestrians' crashes in a district in Hong Kong. A disaggregate Geographical Information Systems (GIS)-based three-dimensional (3D) time-space framework is used to relate individual travel activities with crash patterns. In an attempt to integrate the activity-based and spatial crash analysis models, this study combines three rich relational databases to better describe elderly pedestrian behavior in a road network. In the model calibration, space-time paths of the elderly were first generated, they were then superimposed on crash data which were snapped to the link-node system in a 3D environment, with the additional dimension of the time to supplement the traditional 2D analysis. Finally, one- and four-hourly snapshots of vehicle-pedestrian crashes involving the elderly within the district are derived to identify pos...