The government is ordering the automobile industry to make cars less deadly in side crashes, which kill 8,000 people and seriously injure 24,000 others each year.

The National Highway Traffic Safety Administration issued the complex regulation Wednesday, ending a debate among the industry, safety advocates and bureaucrats that dragged on for a dozen years."It's been a long time coming," Transportation Secretary Samuel K. Skinner said.

The regulation is designed to prevent 500 deaths annually. The protections it requires would lessen the severity of chest and pelvic injuries.

Rules to protect against head injuries are being developed but won't be ready for two or three years, said Jerry R. Curry, head of the traffic safety agency.

Also on the drawing board are standards for light trucks and vans.

The new regulation drew acceptance from the industry and cautious praise from safety advocates.

"We expect to comply fully with it," said Toni Simonetti, spokeswoman for General Motors Corp.

The nation's largest automaker fought NHTSA as the rule developed, contending the dummy used in crash tests was faulty. The agency rejected GM's plea to switch to a dummy the company designed.

Even so, GM became more supportive after a meeting last January between Curry and Robert Stempel, then-president of the company and its current chairman.

Chrysler Corp. considers the regulation "a positive step in the area of auto safety," spokesman John Guiniven said. "We know from our own figures that safety sells."

The changes will boost the average car's cost by about $50. Most manufacturers will add padding or structural strength to doors, and some might do both, Curry said.