Set clear car rules for your teens, just as you would set house rules, and have them sign a contract.

Teens and young adults are the least likely to buckle up, and the most likely to die in auto accidents.

RODALE NEWS, EMMAUS, PA—It’s sounds like good news when you hear that 80 percent of people buckle up when they get into a car, but that still means 1 in 5 are failing to wear seat belts. And many of the beltless riders are teens. A new study, released by the U.S. Department of Transportation just as the May 18 to 31 “Click It or Ticket” campaign was taking place, found that more than 1,600 lives would be saved and 22,000 serious injuries would be avoided each year if the seat belt rate increased to 90 percent in every state.

THE DETAILS: The agency crunched 2007 seat-belt-usage numbers after taking data from the National Highway Traffic Safety Administration (NHTSA)’s National Occupant Protection Use Survey, and also estimated that wearing seat belts prevented more than 15,000 deaths that year. The report, which did not include states and territories with seat belt use at 90 percent or higher (California, Hawaii, Illinois, Iowa, Maryland, Michigan, Nevada, New Jersey, New Mexico, Puerto Rico, Oregon, Texas, and Washington), found that if 90 percent of people in every state wore seat belts, the cost-savings benefit would be huge —$5.2 billion. That’s important, because previous estimates found consumers can pay more than $500 a year for increased costs related to seat-beltless drivers. Taxes, health care, and insurance costs are affected when people (most typically, teenagers) fail to buckle up.

Seat belt use is particularly low among teens and young adults—the group whose leading cause of death is motor vehicle accidents. Of the 4,540 16- to 20-year-olds killed in vehicles in 2007, more than half were unbelted at the time of the crash; 65 percent of victims involved in nighttime crashes weren’t wearing seat belts. “Teenagers are fearless. They don’t think about the costs of not buckling up,” explains Karen Aldana, NHTSA spokeswoman. “Many think they’re invincible, or that they won’t get caught.”