Air bags notwithstanding, auto safety is stuck in neutral. Compared to their huge drop between the mid-1960s and early 1990s, fatality rates have hardly changed in the last decade (see "Safety Slowdown," below), and the raw numbers remain appalling: 42,815 people died on U.S. roads last year, 619 more than in 2001. To improve that safety record, some manufacturers plan to install more-sophisticated driver-warning systems, including radar- and video-based safety devices that sense when you veer over lane markings or too close to other cars-and warn you before it's too late.

Safety Slowdown: The rate of fatal U.S. crashes hasn't much improved in a decade. Above, deaths per 160 million vehicle kilometers traveled.

Unlike previous safety improvements-such as air bags or antilock brakes-which increase the car's ability to protect drivers and passengers from accidents, these new technologies are intended to help avoid accidents in the first place, by giving drivers better information. "We're moving into a new era," says Vicki Neale, a human-factors engineer at Virginia Tech's Transportation Institute. Instead of mechanical systems or devices to protect the car, she says, "the next stages of improvement are going to involve the driver."

To be sure, manufacturers have long considered such devices. Clarence Ditlow, executive director of the Center for Auto Safety, a leading watchdog group in Washington, DC, says such technologies have been prototyped since at least the 1970s but were never implemented-partly because of cost, and partly because there has never been a federal requirement similar to the ones that forced the installation of seat belts and air bags. "Clearly, some of them could have been implemented and should have been implemented," he says. "The industry is not likely to implement them on their own."