Ford Motor Co. will offer inflatable rear seat belts in more of its vehicles starting next summer.
Ford was the first in the industry to offer the belts, which are now available on the 2011 Ford Explorer SUV. The company plans to offer them on the Ford Flex, a seven-passenger crossover wagon, and two unnamed Lincoln vehicles.
Inflatable seat belts look like regular seat belts but with slightly more padding, since the air bag is sewn into them. When the car is in a severe crash, a balloon-like cushion inflates along the belt from the shoulder to the buckle. The belts help prevent chest injuries by distributing the force of the crash over an area that's five times larger than a traditional seat belt. They also cushion the neck.
Ford spent a decade designing and testing the belts. While they fill quickly — in 40 milliseconds — they are less forceful than traditional, steering wheel-mounted air bags because they don't need to bridge the space between the wheel and the person they're protecting. They also fill with cold compressed gas instead of the heat-producing chemical reaction used in traditional air bags. The cold gas and slower speed make the bags safer for young children.
Srini Sundararajan, a safety technical leader at Ford who was primarily responsible for developing the belts, said the company hasn't yet heard of any cases where the belts prevented injuries, but expects to once the new Explorer has been on the road longer. Ford has sold more than 65,000 Explorers since the new SUV went on sale in December.
Ford said 40 percent of Explorer buyers have chosen the inflatable seat belt option. It costs $195 to add the belts to the Explorer XLT, which starts at $31,520.
Sundararajan said Ford is considering adding inflatable seat belts to the front seats, but is still studying how much benefit they would provide.
Ford and a Michigan-based supplier, Key Safety Systems Inc., hold a patent on the inflatable seats belts.
Toyota Motor Corp. has inflatable seat belts made by Takata Corp. in its Lexus LFA sports car, which went on sale after the Explorer.