Nicole R. Nason, the agency's administrator, said that in an effort to persuade more motorists to buckle up after dark, the national "Click It or Ticket" seat belt campaign will this year focus on nighttime belt use.

The study released today showed that nationwide in 2005, more than 15,000 passenger vehicle occupants died in crashes that occurred between 6 p.m. and 6 a.m., and almost two-thirds of those killed were not wearing seat belts.

In Hawai'i, the percentage of people not wearing seat belts killed in nighttime accidents were almost identical to the national average.

The state had 46 traffic deaths occurring at night in 2005. In 68 percent of those fatalities the vehicle occupant was not wearing a seat belt. During the day, 19 people died in crashes, with four were not wearing seat belts. The time of day was not known for another four fatalities but all four were wearing seat belts.

The agency said other survey data showed that nighttime seat belt use is often 10 percent lower than the national average of 82 percent daytime use.

"It's alarming that fewer people are buckling up at night, a time when the odds of being killed in a motor vehicle crash triple," Nason said.

"This year, law enforcement officials will be ticketing violators who are not wearing their seat belts, especially during evening hours."

The Hawai'i Department of Transportation and all four county police departments will run their seat belt enforcement campaign from May 21 to June 3.

Hawai'i's seat belt law requires people in the front seats to use their seat belts and those age 17 and younger to use seat belts in the back seat.

The fine for not wearing a seat belt is $92.