Pedestrian fatality risk as a function of tram impact speed

Abstract

The objective of the presented research-work was to develop a model to describe the risk of fatal accident involving tram and pedestrian. This study extends research concerning relationships between the “impact speed” and probability of pedestrian death in case of tram accident. Over 400 “tram-pedestrian” accidents were analyzed. Logistic regression analysis was used in these studies. The main objective of the research is to compare the risk of fatal accidents when pedestrians are struck by passenger cars and trams. GPS system from trams is used to analyze correlation between the tram speed and different conditions along the public transport stop areas (e.g. traffic signals, priority, and platforms localization). The results show that the fatal risk of hitting pedestrians by a tram running at a speed of 50 km/h is two and a half times greater than that by a car. Research clearly proves that comparing to car impact speed, there is much higher probability of death when pedestrian is hit by a tram running at a speed of 30 km/h – almost 40% (compared to 5% when hit by car). There are even cases of deaths with a very low speed of tram (5–10 km/h).

Tram to Pedestrian Collisions—Priorities and Potentials

“…However, injury severity for pedestrians is higher in tram-pedestrian accidents than in accidents with other motor vehicles. This particular higher injury risk has been documented in a number of studies, such as Hedelin et al, 2002;Margaritis, 2007;Naznin et al, 2016b;Chevalier et al, 2019, andGaca andFranek, 2021.…”

“…The most serious injuries occur when pedestrians are run over (Hedelin et al, 1996). In general, the severity of tram-pedestrian accidents is primarily affected by vehicle related factors, especially by the mass difference between a tram and a human (a tram vehicle can weigh up to 50 tonnes) and ergonomics and stiffness of the vehicle's front (Hedelin et al, 1996;Grzebieta and Rechnitzer, 2000;Margaritis, 2007;COST, 2015;Gaca and Franek, 2021). A simulation study by Chevalier et al, 2019 on the effects on pedestrian injury by tram front-end shape, showed that the injury risk is more severe for the head than any other body region.…”

“…Margaritis (2007) discusses the function of the front under-run protection-he notes that it is more effective at low tram speeds. The injury severity is further affected by the secondary impact, i.e., the physical infrastructure or railway equipment, respectively, the pedestrian hits following the primary impact (Gaca and Franek, 2021). Human factors, such as age, might play a role as well, as exclusively elderly people were found to be involved in fatal tram accidents investigated by Currie et al, 2011. The recently published Technical Recommendation 17,420 (Technical Committee CEN/TC, 2019) defines pedestrian tram front design safety requirements for the first time, mainly based on geometrical guidelines.…”

Assessment of Pedestrians’ Head and Lower Limb Injuries in Tram–Pedestrian Collisions

“…Pedestrians face a higher risk of death when involved in tram collisions compared with automobile collisions at the same speed. Even at low impact speeds of 5-10 km/h, fatalities can occur due to the tram's front ergonomics, which lead to the full transfer of energy to the weak pedestrian body [6]. Therefore, it is necessary to investigate pedestrians' injuries in tram-pedestrian collisions.…”

“…The areas with the highest risk of tram-pedestrian collisions are public transport spots and pedestrian crossings [6]. Since tram drivers often operate their vehicles at low speeds due to caution, pedestrians may have a false sense of security and be unaware of the potential crash risk, resulting in risky situations [7].…”