Crash test dummies have just one purpose - to save countless lives every year. Thanks to them, we have safety belts, air bags and crumple zones. Crash tests were initially carried out on real people, animals or animal carcasses. Nowadays, the dummies are packed with technology and cost up to one million US dollars. Great Inventions looks back at the early testing using humans and pigs and shows how much high-tech equipment is needed to make our lives safer.