What are "passive restraints"?

What are "passive restraints"?

Reed Berry (Driving Expert) gives expert video advice on: Do I have to wear my seat belt? and more...

Everybody's familiar with some of the restraint systems in cars, like traditional seatbelts, but some cars, and I don't know why they did it, automatically wrapped around you when you closed the door. I was almost decapitated by such a restraint system in a rental car, trying to find out where the gas tank was. But these restraint systems wrap around you. The part of the restraint system that wraps around you is basically the shoulder belt. You still have to be responsible for buckling the lap belt, because unless you wear the whole passenger restraint system, the whole seatbelt, it will not protect you.