In 1988, following a series of fatal crashes on U.S. Route 322, Pennsylvania's governor directed Pennsylvania's secretary of transportation to develop immediate, short-term measures to improve safety on the roadway. In response, the Pennsylvania Department of Transportation (PennDOT) led a multidisciplinary team that developed a fourteen-point safety plan for the corridor. PennDOT immediately declared the initiative a success and implemented similar efforts statewide. The Federal Highway Administration heard about these programs, named Corridor Safety Improvement Programs (CSIPs), and encouraged other states to use them. Following Pennsylvania, numerous states, including Virginia and California, developed CSIPs. Further, in 1997, a series of fatal crashes on U.S. Route 28 in Virginia led to Virginia's governor directing Virginia's secretary of transportation to improve safety on the roadway, as had happened in Pennsylvania. This study investigates these safety efforts to determine the factors associated with effectiveness. The researcher presents model guidelines for developing effective corridor safety programs.