In most head-on accidents, the pedestrian's head smashes onto the windshield or against engine parts, through the hood. "If you don't do anything, you have a 50 percent chance of life-threatening injury," says Yngve HŒland, Autoliv's research director. To improve the odds, the company devised a system that senses a pedestrian impact and inflates a pair of steel bellows that props the hood up by four inches in just 70 milliseconds. The person's head then tends to strike the resilient sheet metal of the hood, which can absorb much of the energy of the impact. Autoliv has also tested external air bags that deploy from the windshield pillars to soften the landing of a crash-victim's head.
Together, these two safety devices reduce the likelihood of a fatal injury to 15 percent, judging from crash-dummy simulations. The European Parliament is considering safety guidelines that would most likely require automakers to incorporate such pedestrian-protection systems by mid-2005. No such rules are pending in the United States, but American and Japanese manufacturers are beginning to experiment with similar technologies.


