In 1960, 4.6 people were killed for every 100 million passenger-vehicle miles on America's highways. Today, according to NHTSA, the fatality rate is 1.25 deaths per 100 million miles.

The improvements include obvious things such as padded dashboards, air bags, child safety seats and shoulder belts, and some things most people never notice, such as better adhesives that help keep windshields - and passengers - in cars in crashes