Crashworthiness Evaluation of Light Rail Vehicle Interiors

Abstract

Statistically, light rail transit (LRT) systems have higher injury rates on a per‐passenger‐mile basis than heavy rail and commuter rail systems, because in most cities, light rail vehicles (LRVs) operate on city streets. Passenger safety is dependent on the configuration and severity of the accident, as well as the degree of crashworthiness engineered in the overall vehicle design. Passengers can be injured or killed as the result of two main mechanisms that arise because of sudden acceleration or deceleration of a vehicle, or because of mechanical damage to the vehicle structure. These mechanisms are the following: (1) primary collision of the vehicle with another vehicle or obstacle, which results in two main outcomes: occupant‐compartment crush and consequent reduction of survival space, or penetration of the compartment by parts of the impacting vehicle; and (2) secondary impacts between the occupant and the interior of the vehicle (compartment interior surfaces, other occupants, or loose objects) that occur after initiation of the primary collision. The objective of this research is to identify the injury mechanisms to passengers in LRVs and to propose future areas of research that will lay the foundation necessary to generate transit rail vehicle interior design guidelines that enhance the safety of passengers during collisions. Results of this study show that the most common and severe injuries to LRV passengers involve the head, neck (neck extension, flexion, shear, and compression), and femur (compression) regions. These injuries are primarily the result of body‐to‐body contact between unrestrained passengers and/or body‐to‐seat structure contacts.