For years, reducing the number of traffic-related fatalities and injuries has been a major problem throughout the world. Today, it has gained much more momentum in view of rapidly increasing SUV, van, and light-truck populations relative to the number of passenger cars, and due to significant improvements in technologies that facilitate a better understanding of the interaction dynamics among widely differing size vehicles. Unless disparities in crashworthiness among vehicles of different masses, sizes, and structural characteristics in mixed crash environments are successfully taken into account, the challenge toward improved vehicle safety will continue. This two-part compendium provides the most comprehensive information available on the entire spectrum of vehicle crash compatibility. The first part presents oral comments captured from the 2003 SAE World Congress panel discussion on compatibility. The panel of leading experts representing industry, academia, and government provides a rough framework and a broad range of views on current and emerging developments in compatibility research. The second part of this compendium features 44 best technical papers from SAE International and the International Technical Conference on the Enhanced Safety of Vehicles, published from the early 1970s through 2004. Readers will get a feel for the direction passenger car and heavy-vehicle manufacturers, research institutions, infrastructure suppliers, insurers, and governments are taking to reduce the number of traffic fatalities and injuries.