Reducing fatalities in traffic is one of the main goals of the automotive industry. Today, active safety systems are gaining more importance – but passive safety system still builds the basis, when it comes to an accident. The today’s detection of a crash is based on acceleration and pressure sensors and has some deficits related to the measurement principles. Detection of the severity and direction of the crash are not optimal. This paper presents a new approach to crash detection based on passive RFID tags. Therefore critical requirements are specified and are compared to what passive RFID technology is able to do. The idea of this approach is supported by first measurements for communication performance and robustness. In the end essential benefits are shown.