A historical review of frontal and side impact regulations in the U.S.A. and Europe has been conducted. The biomechanical bases of injury criteria utilized in these regulations have been examined. It is shown that the biomechanical database utilized in the current impact regulations are based on research conducted before the mid-1980s. Research conducted since then has not had much of an impact on regulatory injury criteria, although upgrades in the US FMVSS 208 and the FMVSS 214 have attempted to synthesize all available data to develop tolerance levels for various size dummies.