Abstract: A supplemental restraint deployment method utilizes measured vehicle speed and acceleration and the output of a closing velocity sensor that detects the presence and closing rate of an approaching object prior to contact with the vehicle. The closing velocity and vehicle speed are utilized for classification of an impending crash event, where the deployment options vary depending on the crash classification. In the ensuing crash event, a classification-dependent algorithm is executed to determine if, when and what level of restraint deployment is warranted based on measures of actual crash severity. Additionally, the algorithm is reset when the calculated change in vehicle velocity reaches the initial closing velocity.