Improvement of Tram-to-Vulnerable Road User (VRU) Crash-Compatibility

Modal shift in urban transportation is forecast to increase the frequency of tram interactions with Vulnerable Road Users (VRUs), who are disproportionately susceptible to injury. This report describes the outcomes of a research programme to identify the limitations of existing tram–VRU crash-compatibility guidelines. A targeted search of Scopus, Google Scholar and the grey literature resources yielded 27 results for inclusion in this study, covering three areas affecting tram–VRU collisions and interactions. These areas were: body regions susceptible to injury, speed and location of reported collisions, and VRU rider preferences around roads and tram infrastructures. This informed recommendations on future tram–VRU crash-compatibility guidelines. Injury criteria correlating to head, thorax and lower extremities should be considered, to enable up to ~78–84% of serious (AIS3+) injuries from real-world tram–pedestrian collisions to be captured in crash-compatibility studies. Although most tram–VRU collisions occur around stops or crossings, increasing vehicle impact speed in testing from 20 km/h to 30 km/h would enable most high-severity injuries from collision data to be captured. Based on VRU-stated or observed preferences, cyclists and e-scooter users should be considered travelling perpendicular to road infrastructures in tram–VRU collisions. Implementation of such recommendations into tram–VRU crash-compatibility guidance would account for a greater proportion of real-world interactions.