U.S. Transportation Secretary Ray LaHood yesterday released updated 2009 fatality and injury data showing that highway deaths fell to 33,808 for the year, the lowest number since 1950.

The record-breaking decline in traffic fatalities occurred even while estimated vehicle miles traveled in 2009 increased by 0.2 percent over 2008 levels.

In addition, 2009 saw the lowest fatality and injury rates ever recorded: 1.13 deaths per 100 million vehicle miles traveled in 2009, compared to 1.26 deaths for 2008.

Fatalities declined in all categories of vehicles including motorcycles, which saw fatalities fall by 850 from 2008, breaking an 11-year cycle of annual increases.

According to a National Highway Traffic Safety Administration (NHTSA) study based on 2006 Centers for Disease Control (CDC) data, motor vehicle crashes are the leading cause of death for those between the ages of 3 and 34.

In addition to the record-breaking drop in fatalities, the number of people injured in motor vehicle crashes in 2009 declined for a 10th straight year in a row, falling an estimated 5.5 percent from 2008, according to NHTSA data released today.

Alcohol impaired driving fatalities declined by 7.4 percent in 2009 – 10,839 compared to 11,711 reported in 2008.

National Highway Traffic Safety Administrator David Strickland noted that drunk driving was still a factor in about one-third of the more than 30,000 traffic deaths each year.

"We will continue to work with our state partners to strictly enforce both seat-belt use and anti-drunk-driving laws across this nation, every day and every night," Strickland said in a statement.

Joan Claybrook, president emeritus at the nonprofit advocacy group Public Citizen, said the poor economy explained the lower death and injury rates.

"When the economy is down, discretionary driving drops substantially," Claybrook said. "The people who are doing the driving are going to work. They're much more serious and more careful."

Improvements in car designs might be another factor, Claybrook said, noting that manufacturers now build SUVs that are lower to the ground, making them more resistant to rollovers, which can be particularly deadly.