A VEHICLE SAFETY SYSTEM

A safety arrangement for a vehicle, the arrangement comprising: a control unit; one or more vehicle sensors, the sensors being connected to the control unit so the control unit receives output signals from the sensors; a road detection arrangement to detect a surface or an edge of a road in the vicinity of the vehicle and determine whether the vehicle has left the road and is being driven over a surrounding non-road surface, or is likely to do so; and one or more vehicle safety systems which may be activated by the control unit, wherein: the control unit is configured to process the signals received from the sensors and to determine whether the vehicle is travelling over rough terrain, or is entering a ditch-like feature, or the vehicle is airborne; the control unit is configured to activate the one or more vehicle safety systems if it is determined from the signals received from the sensors that the vehicle is travelling over rough terrain, or is entering a ditch-like feature, or the vehicle is airborne; and signals from the sensors, or one or more quantities derived or calculated from signals from the sensors, are compared against at least one threshold to determine whether to activate the one or more vehicle safety systems, wherein the threshold is set at a first level if it is determined by the road detection arrangement that the vehicle has not left the road, and is not likely to do so, and at a second level if it is determined that the vehicle has left the road, or is likely to do so.