Safety devices to protect occupants against injury and death have been a primary focus for the automotive industry and governmental agencies. First, it was important to maintain "passenger-compartment integrity" so that occupants remain in the compartment (thanks to door-latches and safety glass) and impacts are deflected. Within the compartment, energy-absorbing devices are in the forms of padded dashboards and visors, energy-absorbing steering columns, cushioned steering wheels, and hinged steering columns. Other energy absorbers have been built into the chassis and body of the car; many of these are stress risers in the frame that buckle on impact. The final group of devices consists of active and passive restraints for the driver and passengers, of which the safety or seat belt may be the best known.

In automotive design, the seat belt may be the perfect proof that everything old is new again. The motor cars of...