This paper on side impact information from the Motors Insurance Corporation (a General Motors subsidiary) accident file first presents some overview statistics and then reviews findings from an in-depth case-by-case analysis of side impacts involving fatal and life-threatening injuries. The overview statistics address questions related to side impact frequency, objects inducing the side damage, the area impacted, the impact configuration, and the impact speed. The in-depth case-by-case analysis focuses specifically on side impact injury mechanisms. Types of countermeasures that may he employed to mitigate injury are discussed. In addition, vehicle test procedures that may address the widest spectrum of field accident conditions are suggested. It is concluded from this study that a subsystem test strategy more comprehensively addresses the injury spectrum, and should produce greater benefits in terms of injury reduction, than do either the current U.S. MVSS 214 Regulation or full-vehicle test.