Autoliv's Active Seatbelt has a pre-pretensioner that gives a more gentle load on the occupants chest in the event of a crash. A high-speed electrical motor tightens the seat belt as early as one tenth of a second before a likely crash, using the vehicles electronic stability sensor, a panic-braking sensor, or a pre-crash radar to start the belt tightening.

The elimination of slack in the belt system can therefore start earlier and yet be more efficient without increasing the load on the occupants ribs. The system is reversible. Consequently, it is possible to tighten the belt as a precaution when it is difficult to predict whether there will be a crash or not. It is also possible to use the Active Seatbelt to warn the driver by vibrating the belt, for instance, if the driver enters a curvy road at a too high speed. The seatbelt's motor also improves comfort by softly thightening the belt when buckling up.