Study of the possible relationships between tramway front-end geometry and pedestrian injury risk

Chevalier, Marie-Christine; Brizard, Denis; Beillas, Philippe · 2019 · Crossref

DOI: 10.1080/15389588.2018.1536823

archive: archived pipeline: cataloged verified

Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)

Summary

This study investigates the relationship between tramway front-end geometry and pedestrian injury risk, addressing a critical safety gap as tramway networks expand globally. While pedestrian protection regulations exist for cars and trucks, no equivalent standards govern tramways, despite pedestrians accounting for half of all tramway injury victims. The research aims to identify geometric design parameters that minimize injury risk, particularly head injuries, across a wide range of possible tramway shapes and pedestrian sizes. The researchers employed a computational simulation approach using the MADYMO multibody solver. They developed a parametrized model of the tramway front-end, idealized as two planar surfaces (windshield and fairing) defined by six geometric parameters, including windshield height, offset, and angles. This model was tested against four pedestrian models representing different sizes: 5th percentile female, 50th percentile male, 95th percentile male, and a 6-year-old child. A full factorial design generated 1,440 tramway geometries, resulting in 8,840 total simulations at impact velocities of 20 km/h and 30 km/h. Custom Python scripts automated the generation, execution, and post-processing of these simulations. Injury criteria included Head Injury Criterion (HIC) for the head, compression for the thorax, and various metrics for lower extremities. The results indicated that the head was the most vulnerable body region, with the thorax showing the lowest injury risk. Two antagonist kinematic mechanisms influenced head impact velocity: trunk rotation caused by lower body engagement, which increased head velocity and HIC values, and shoulder loading, which accelerated the upper body away from the windshield, reducing impact velocity. The study found that windshield height and offset were the most influential geometric parameters. A combination of a high windshield (1.3 m) and a large offset (0.2 m) provided the best compromise for minimizing head injury risk across all pedestrian sizes at 20 km/h. Conversely, low windshield heights (below 1.05 m) combined with large offsets were particularly unfavorable. Increasing the impact velocity to 30 km/h significantly elevated injury risks, with 75% of configurations exceeding the HIC threshold for the 50th percentile male. The findings suggest that tramway design should prioritize geometries that promote shoulder loading to mitigate head impact velocity. However, because optimal designs vary by pedestrian size, no single configuration performed equally well for all groups. The study concludes that while geometric optimization is beneficial, the high stiffness of current tramway windshields poses a significant barrier to safety, especially at higher speeds. Future improvements in pedestrian safety may require regulatory changes to reduce windshield stiffness or impact speeds, alongside the adoption of more advanced injury criteria.

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed.

Summary generated by qwen3.6-27b-prismaquant on 2026-06-26; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• vru crash typology