The simple belt that was pulled across the lap (and that only came on the front seats) has long since been retired. That belt was known as two-point because of its simple A-to-B design. Today’s seat belts are three-point; one strap goes across the lap while another goes over the shoulder and diagonally across the chest. In some automobiles, the two straps are connected and the occupant crosses it over the chest and the lap in one motion. In other cars, the occupant connects the lap belt while the shoulder belt slides into place automatically once the door is closed. A prototype for a four-point is being developed; it works more like a harness than a typical seat belt would.
Seat belts are made of lightweight but durable fabric that is designed to withstand impacts and hold the wearer in place. Of the roughly 40,000 automobile deaths that occur each year, safety experts say nearly half could have been prevented if a seat belt was being worn. In many cases, the person is killed as a result of being thrown from the vehicle upon crashing. In addition to being durable, seat belts are also designed to be much more comfortable than they were in the past. Most seat belts today employ a mechanism that allows the wearer to move fairly comfortably while driving; if the car comes to a sudden stop the belt locks and holds the wearer firmly in place.