Traffic travels Monday on I-24 near Nickajack Lake.

NASHVILLE -- Tennessee recorded the fewest traffic deaths in 48 years during 2011, according to preliminary figures released Thursday by the Tennessee Department of Safety and Homeland Security.

There were 947 traffic-related deaths last year on Tennessee roads. It was the lowest number of recorded fatalities since 941 in 1963.

The 2011 dip was the third time in 48 years that crash-related deaths dipped below 1,000. Since 2006, fatalities have dropped 26.2 percent with truck-related fatalities falling 34.5 percent. Bicyclist deaths fell 28.6 percent. Motorcycle deaths dropped 19.1 percent and the number of pedestrians killed fell 4.5 percent.

Department officials say 2011 arrests of impaired drivers rose 39 percent over 2010. Drunken driving deaths dropped 31.6 percent from 2006 to 2010.

But officials said in their news release that seat belt usage remains a "major concern." While data indicates safety-belt usage was 87.4 percent in 2011, 56.3 percent of people who died in vehicle crashes did not buckle up.

"The 2011 decline in vehicular fatalities is a credit to the hard work and dedication of the Tennessee Highway Patrol and other law enforcement agencies, as well as a successful partnership with the Governor's Highway Safety Office," Commissioner Bill Gibbons said. "We are deploying state troopers on a proactive basis to maximize the impact on public safety. The dramatic increase in DUI arrests reflects that effort on our part."