Washington continues to be a national leader in seat belt use, according to a recent survey by the National Highway Traffic Safety Administration. In fact, seat belt use among drivers in this state is higher this year than it was last year, said the Washington Traffic Safety Commission.

Last year, the state commission estimated about 96.3 percent of drivers across the state used their seat belts. This year, the figure inched to 96.4 percent.

Last year's figure was the highest in the nation, said state commission spokeswoman Jonna VanDyk.

Seat belt use nationwide was 81 percent in 2006, as measured by NHTSA's National Occupant Protection Use Survey. A nationwide observational research survey of seat belt use is conducted annually by the NHTSA.

This year's Washington survey, conducted in July, included 100,532 vehicle drivers and passengers on a variety of road types following research guidelines established by the NHTSA.

So why is usage so high here?

"You can't really know for sure," VanDyk said. But she speculates this state's primary seat belt law, stiff fines for not being buckled up, active patrol and enforcement, and an aggressive statewide public information campaign may be factors.

"We have all four, and we're working all four all the time," she said.

In June 2002, when Washington's primary seat belt law went into effect, about 82 percent of drivers wore seat belts. The primary seat-belt law gives officers authority to pull over unbuckled motorists. Since the adoption of the law and the launch of "Click it or Ticket" crackdowns, seat belt use has climbed steadily, said VanDyk.

Studies show that seat belts reduce serious injuries from crashes by 69 percent, and deaths by 45 percent, according to the commission.

In May, local law enforcement agencies announced nighttime patrols would be added to the statewide "Click it or Ticket" crackdown on unbuckled motorists. The Traffic Safety Commission said the nighttime death rate was four times what it was during the day because seat-belt use was lower, perhaps partly because many folks figured police couldn't see unbuckled motorists at night.

Studies conducted in Washington indicated that medical costs from collisions amount to more than $276 million each year. An unbelted vehicle occupant's medical costs average $11,000 more per collision than those of a belted vehicle occupant's, says the state commission.

Other states with high seat belt use include Oregon and Michigan. Seat belt use was lowest, according to the survey, in Wyoming and New Hampshire. VanDyk said Western states generally tended to rate higher than others parts of the country.