To share Thanksgiving dinner with relatives and friends, about 29 million Americans will get in their cars this weekend and drive 100 miles or more.

The National Safety Council estimates 380 to 480 of them will die in traffic accidents, and 17,000 to 21,000 people will be injured.

"People face risk when driving not only during the holidays but throughout the year," says Chuck Hurley, executive director of federal affairs for the National Safety Council. "And people go through a risk denial process because they want to believe an accident will not happen to them."

Hurley says there are three principal risk factors involved when driving: whether a seat belt is used, the speed of the car, and alcohol consumption.

"There are 100 million people now covered by mandatory adult seat belt laws, and all 50 states now have laws requiring the use of child safety seats," Hurley said. "So buckle your seat belts."

As for speed, Hurley says, "for every 10 mph above 50 mph, the chance of a fatality doubles."

Hurley cautions people from driving between 10 p.m. and 2 a.m. on the weekend, when the greatest proportion of drunk drivers are on the road. "Ten percent of the people on the road at this time are legally intoxicated," he said.

During Thanksgiving, as well as other holidays, many people travel with their children and car accidents are the leading cause of death for children under 5.

District law requires children under 3 to be in car seats and children 3 to 6 years of age to wear seat belts.

"When you put a child in a car seat, make sure it is used properly," says Elaine Weinstein, executive director of the National Child Passenger Safety Association. "Most parents don't read the manufacturer's instructions and put the seat belt in the wrong place."

Weinstein also advises checking the safety harness in the car seat because if it is too loose, there is nothing holding the child in the seat. "The whole key to surviving an accident is to keep your head and chest away from hitting any part of the inside of the car," she says.

For more information on child car safety call: 429-0515. Travel tips brochures are available free by sending a self-addressed, stamped envelope to: National Child Passenger Safety Association, P.O. Box 65616, Washington, D.C. 20035-5616.

To rent an infant car seat, call 724-4585 in the District, (301) 225-1376 in Maryland, and 1-800-533-1892 in Virginia. -- Wendy Melillo