A collision detection system (1) for detecting and assessing the state of a crash guard (2), comprising at least one crash guard (2), which is provided with a sensor for detecting a collision onto or against the said crash guard (2), wherein the said system comprises a processing unit, which is provided to assess, on the basis of the signals generated by the sensor, the effect of a collision on the crash guard (2) and, if necessary, to initiate an alarm signal.