.The present Study sets forth criteria for the design of airport safety areas and land uses therein. The Study has been in preparation and in real-world testing and verification since 1972. Its prototype was developed by the writer for the Airport Land Use Commission (ALUC) of the County of Santa Clara, California, which adopted the criteria established by the Study during 1973. The accident-potential concepts underlying the 1972 Study were also adopted and incorporated by the U.S. Department of Defense in its AICUZ policies and guidelines.The present Study embodies two new developments in the design of airport safety areas, namely: 1A separation within “primary airport safety areas,” that extend beyond the ends of airport runways, between (a)areas in which the number of people on the ground exposed to the impact of crashing or crash-landing airplanes is reduced to a minimum while the value of the land is protected by judicious less impact-sensitive use; (b)areas in which the safety of crashing or crash-landing airplanes and their occupants, as well as people on the ground, is safeguarded to the highest possible extent. 2The tracing of other airport safety areas, newly termed by the author “transitional airport safety areas,” in which mass assemblies of people should be proscribed.