The Transportation Department said late Wednesday that traffic deaths fell 9.7 percent in 2009 to 33,808, the lowest number since 1950. In 2008, an estimated 37,423 people died on the highways.
Transportation Secretary Ray LaHood said the annual report "shows that America's roads are the safest they've ever been. But they must be safer. And we will not rest until they are."
Forty-one states, the District of Columbia and Puerto Rico saw reductions in highway fatalities, led by Florida with 422 fewer deaths and Texas, down 405.
The rate of deaths per 100 million miles traveled also dropped to a record low. It fell to 1.13 deaths per 100 million miles in 2009, compared with 1.26 the year before.
Year-to-year declines in highway deaths have occurred in previous economic downturns, when fewer people are out on the road. Traffic deaths decreased in the early 1980s and early 1990s when difficult economic conditions led many drivers to cut back on discretionary travel.
But last year's reduction in fatalities came even as the estimated number of miles traveled by motorists in 2009 increased 0.2 percent over 2008 levels.
Barbara Harsha, executive director for the Governors Highway Safety Association, attributed the improvements to more motorists wearing seat belts, better enforcement of drunken driving laws and enhanced vehicle safety features.
Side air bags that protect the head and midsection are becoming standard equipment on many new vehicles. And electronic stability control, which helps motorists avoid rollover crashes, is more common on new cars and trucks.
LaHood has sought to crack down on distracted driving, urging states to adopt stringent laws against sending text messages from behind the wheel, as well as other distractions.
Harsha said LaHood's "focus on distracted driving has brought an unprecedented focus to behavioral highway safety, and as a result, lives are being saved."
The annual highway safety report also found: