This article represents the first paper in a two-part series dealing with safety during tram–pedestrian collisions. This research is dedicated to the safety of trams for pedestrians during collisions and is motivated by the increased number of lethal cases. The first part of this paper includes an overview of tram face development from the earliest designs to the current ones in use and, at the same time, provides a synopsis and explanation of the technical context, including a link to current and forthcoming legislation. The historical design development can be characterised by three steps, from an almost vertical front face, to leaned and pointed shapes, to the current inclined low-edged windshield without a protruding coupler. However, since most major manufacturers now export their products worldwide and customisation is only of a technically insignificant nature, our conclusions are generalisable (supported by the example of Berlin). The most advantageous shape of the tram’s front, minimising the effects on pedestrians in all collision phases, has evolved rather spontaneously and was unprompted, and it is now being built into the European Commission regulations. The goal of the second part of this paper is to conduct a series of tram–pedestrian collisions with a focus on the frontal and side impacts using a crash test dummy (anthropomorphic test device—ATD). Four tram types approaching the collision at four different impact speeds (5 km/h, 10 km/h, 15 km/h, and 20 km/h) were used. The primary outcome variable was the resultant head acceleration. The risk and severity of possible head injuries were assessed using the head injury criterion (HIC₁₅) and its linkage to the injury level on the Abbreviated Injury Scale (AIS). The results showed increasing head impacts with an increasing speed for all tram types and collision scenarios. Higher values of head acceleration were reached during the frontal impact (17–124 g) compared to the side one (2–84 g). The HIC₁₅ values did not exceed the value of 300 for any experimental setting, and the probability of AIS4+ injuries did not exceed 10%. The outcomes of tram–pedestrian collisions can be influenced by the ATD’s position and orientation, the impact speed and front-end design of trams, and the site of initial contact.

To satisfy the needs of growing urban populations, mitigate the impacts of climate change, and improve the environmental conditions and quality of life in cities, there has been an increasing demand for public transport, especially effective and economically beneficial trams. As a consequence, the issue of pedestrians’ safety has become more important because of a higher risk of tram-pedestrian collisions. The article is focused on the development of a computational model that can accurately simulate such collisions, and its challenges and limitations. Experiments were conducted using various types of trams, different impact speeds, and an anthropomorphic test device (dummy). Computational models of the tram front ends were created based on CAD geometry supplied by VÚKV a.s. The finite-element mesh itself used a combination of 1D, 2D, and 3D elements. Depending on the shape of the individual components, TRIA, QUAD, HEX, PENTA, and TETRA elements were used for modeling. The results showed that the consequences of these collisions are sensitive to small differences in the posture of the dummies. Therefore, it is difficult to identify a generally more pedestrian-friendly shape for trams using the dummy-tram crash test method.

The paper is focused on the dynamic response of Hybrid III crash-test dummy during low-severity frontal (forehead) and side (temple) head impacts. The measurements used a pedestrian dummy (Hybrid III 50th percentile male dummy, Jasti Co., ltd., Tokyo, Japan) and a unique pendulum impact testing machine (impactor) of own design and construction. The tests were conducted at two various impact intensities (velocities) that did not exceed the speed of 1.6 m/s. The primary outcome variable was a resultant magnitude of acceleration measured on the vertex of dummy's head and the results were compared to 11 human volunteers. The goal of the study was to analyse the biofidelity of Hybrid III Dummy in a pedestrian setting during low-severity frontal and side head impacts by comparing the dynamics and kinematics of the dummy's head to human volunteers.