The present invention relates to a vehicle safety system and method including a detection system, an emergency control unit and one or more safety devices. The detection system detects a target vehicle positioned longitudinally and laterally displaced relative the detection system, and defines a target vehicle rectangle that at least partly encloses the target vehicle, and constitutes an approximation of the target vehicle. The target vehicle rectangle forms a boundary (k) positioned along a second bearing having a second azimuth angle (δ′1+δ′2) with reference to a first reference line. The target vehicle rectangle forms a first corner (j) closest to the detection system and positioned along a first bearing having a first azimuth angle (δ′1) with reference to the first reference line. The detection system calculates a yaw movement (θA) of the target vehicle using the first and second azimuth angles (δ′1, δ′1+δ′2).