Development of Proposed Crash Test Procedures for Ambulance Vehicles

Ambulance vehicles are a unique passenger environment with complex crashworthiness and occupant protection issues, eg. occupants in various orientations, unique human factors aspects and an array of aftermarket interior modifications. In the USA, ambulance vehicle occupant protection, crashworthiness and safety testing lags 30 years behind current general automotive safety technology. This paper proposes crash test procedures and outlines some of the challenges faced for such vehicles based on manufacturer and consumer conducted pre-modification crash tests and previous ambulance sled and full scale crash tests. A typical ambulance vehicle from one of the largest fleets globally, was addressed. Based on manufacturer specifications, crash test data for the vehicle, inspections and other published data regarding ambulance vehicle crashes, sled and crash testing were considered – an approach to an impact testing procedure is outlined and developed by a multidisciplinary team. Assessment and development focused on vehicle crashworthiness performance and real world human factors aspects of aftermarket interior modifications. Frontal and side impact crashworthiness testing profiles for this vehicle were determined and developed inline with parameters outlined in ASA 4535 (ambulance restraint systems standard) and the CEN 1789 standard. The testing profiles include a recumbent occupant, rear and forward facing seated occupants, 50 and 95 percentile ATDs, including side impact ATDs for seating positions exposed to side impacts. The authors propose that ambulance vehicle safety testing and design should be driven by accepted automotive safety practice. In a setting of high crash rates, a complex occupant and emergency care environment, and the absence of prescribed dynamic crashworthiness test procedures for ambulances the proposed test procedures in this paper provide a first approach to describe the approach to the technical development of comprehensive crash testing profiles in this setting. Such profiles for this environment will ensure that system safety can be ascertained and optimized for these vehicles, and support safety enhancements and occupant protection for ambulance vehicle development.