Tram to Pedestrian Collisions – Priorities and Potentials

Christian Lackner’s first publication is now online.  The main goal was to raise awareness about possible injuries in public road traffic and to find out how to improve the safety of future trams using human body models in explicit finite element simulations.

To improve mobility in cities in line with environmental goals, in urban traffic, trams represent an increasingly important means of transport. Due to the close interaction with other road users, this makes collisions with trams fairly frequent. This study has investigated accidents between trams and vulnerable road users resulting in personal injury, aimed at identifying priorities for simulating collisions between trams and pedestrians to assess passive safety measures. Tram accident data collection established throughout Europe from multiple sources and with varying degree of details, have been combined and analysed. These analyses comprise risk assessments per km-driven and general tram accident partner and site type evaluations, with more detailed analyses on accident site distance to the closest tram stop and injured body regions, respectively. In total, 7,535 tram-pedestrian accident resulting in 8,802 pedestrian injuries, collected in the year 2000–2021, was analysed. Accident risk ranges from 0.934 accidents per number of tram (million) km-driven, for slight injuries to 0.063 for fatal injuries. Pedestrians represent a large proportion of tram accident collision partners, especially for severe and fatal accidents. In accidents between trams and pedestrians, 3% of reported injuries are fatal, 23% severe and 74% minor. Generally, low-speed accidents close to tram stops often leading to minor injuries were observed to be of significant importance (<20m to the GPS location of a stop). Analysis of accidents was done bases on gender of the pedestrian showing overall similar involvements in accident with slight difference for various age groups and sites. Regardless of injury severity, the most frequently injured body region in accidents involving a tram is the head. Likewise, injuries sustained to the thorax, especially for higher injury severities are of high relevance, followed by injuries to the lower extremities. Based on this study, recommendations for developing reasonable tram-pedestrian accident scenarios for virtual testing can be derived for further optimisation of pedestrian safety of trams.

Tram accidents involving VRUs are prevalent in urban areas across Europe. The overall average risk for tram pedestrian accidents per million tram kilometres travelled resulting in minor, severe and fatal injuries, is 0.934, 0.448 and 0.063, respectively. The data analysis of accidents involving trams shows that pedestrians clearly account for the largest proportion of fatal injuries, directly followed by cyclists. The various countries in this study show differences in typical tram-pedestrian accident locations though tram stops generally tend to predominate. Regarding the age of pedestrians involved in tram accidents, the accident data show a significant peak for the age group 15–24, however the group older than 75 years also shows a strikingly high involvement. In terms of injured body regions, the head shows the highest rate of AIS2+ and AIS3+ injuries for both males and females.

The analysed data can be used to derive representative virtual testing scenarios, that can be used in the future for utilising the latest analysis techniques, like HBM simulations, to further optimise the pedestrian-safety of trams.

Tram to Pedestrian Collisions – Priorities and Potentials is written by Christian Lackner, Philipp Heinzl, Maria C. Rizzi, Christoph Leo, Martin Schachner, Petr Pokorny, Peter Klager, David Buetzer, Rune Elvik, Astrid Linder and Corina Klug, published in Frontiers in Future Transporation.