Does locking your car doors make you safer in the event of an accident?

Yes, locked doors protect you in case of an accident. In the event of an accident, an unlocked door may open. If you are not wearing your seat belt securely, you could be thrown out of the vehicle and seriously injured. On the other hand, if you lock the door and your car has an accident, the combination of a seatbelt and a locked door will keep you safe inside.

In addition, a locked door helps keep your car's body intact in the event of an accident, protecting you. Locked doors also keep the roof from collapsing if the car rolls over. It is true that even locked doors will swing open if loads are exceeded, but it is equally true that these tolerances are quite high, on the order of pressures in excess of 2,500 pounds.