Crashworthiness Evaluation Roof Strength Test Protocol (Version I)

Roof strength evaluations consist of a quasi-static test conducted on a vehicle’s roof in a manner similar to tests used to judge compliance with Federal Motor Vehicle Safety Standard 216 (Office of the Federal Register, 2009). The main differences between the procedure specified by the Insurance Institute for Highway Safety (IIHS) and that specified by the US federal government are that the IIHS procedure: • specifies testing one side of a vehicle’s roof, • does not include a headroom criterion, • specifies testing to a given displacement instead of a given force level, and • specifies setting the vehicle’s pitch angle during testing based on the measured on-road pitch angle. An overall rating is assigned based on the peak strength-to-weight ratio (SWR) measured within 127 mm of plate displacement. Test Vehicle Selection and Curb Weight Measurement Curb weight values used for calculating SWR are based on IIHS measurements of a vehicle, not the manufacturer’s specified curb weight. For each vehicle model, the specific trim level selected for measurement is the one that most closely meets the IIHS definition of a “typical” vehicle of that class. This definition is made for each class by listing the presence or absence of certain features in a prioritized order. As an example, the following were the requirements for small SUVs in 2009: 1. 4-wheel driv