Method for controlling a time of activation of a reversible restraint system in a vehicle

The present disclosure relates to a method for controlling a time of activation of a restraint system (15, 15') in a vehicle (3), the vehicle comprising a seat belt (9) associated to a seat (5), the restraint system being a reversible restraint system, the method comprising the steps of a) determining a current length (L) of pulled out seat belt (9), b) detecting a collision or an imminent collision involving the vehicle (3), c) predicting a time (T 0 ) when the collision is predicted to affect a user (7) of the seat belt (9), d) activating the reversible restraint system (15, 15') a selectable time period ( 1 ) before the time (T 0 ) when the collision is predicted to affect the user (7) of the seat belt (9), wherein a length of the selectable time period ( 1 ) is a function of the determined current length (L) of pulled out seat belt (9). The disclosure further relates to a safety arrangement (1, 1') of a vehicle (3).