A car that has been pried open rests against a fire truck early May 7 in San Bernadino, Calif. The driver was seriously hurt. The crash occurred as firefighters were finishing an emergency call. (AP/AP)

The steady descent in deaths on the nation’s roadways continued last year, resulting in the lowest number since 1949, the National Highway Traffic Safety Administration said Monday.

Preliminary projections released by the federal agency showed that 32,310 people died in crashes last year, a decrease of 375 deaths from 2010. It is the sixth consecutive year of decline since 2005, when deaths reached a recent high of 43,510.

The steady slide initially was attributed to the economic downturn, but the decline has continued even as Americans rebounded from a 2009 low and began driving more miles in 2010 and last year.

“There’s no magic bullet but rather a combination of factors contributing to the decline,” said Jonathan Adkins, spokesman for the Governors Highway Safety Association, a national group of state highway safety officials. “These include high seat belt use, safer cars and safer roads. Also, the continued high gas prices and high unemployment are no doubt also factors. We suspect that optional trips, such as those taken by teens, are also are occurring less frequently, so that may be a factor, too.”

Increased use of cameras to catch drivers running red lights and speeding also has been cited for reducing accidents.

Final numbers for the year will be calculated once state agencies forward complete data for the fourth quarter of 2011. The death count for 2010 was increased by 97 when the revised tally was released in December of last year.