A vehicle safety system comprising: at least one occupant safety device (6) for protecting an occupant of the vehicle (1) in the event of a side impact; and a control unit (7) operable to receive information from one or more vehicle sensors (2, 3, 4, 5) and to provide a trigger signal to activate the occupant safety device (6). Under normal driving conditions, a default deployment algorithm is used by the control unit (7) to determine whether the trigger signal should be generated; and if it is determined that loss of control of the vehicle (1) is occurring, or is expected to occur, and the longitudinal speed of the vehicle (1) exceeds a first threshold, the control unit (7) employs a first further deployment algorithm to determine whether the trigger signal should be generated. The first further deployment algorithm being adapted to cause the trigger signal to be generated a shorter time after the initiation of a side impact than is the case for the default deployment algorithm.