WASHINGTON, US (AFP) - Around 109 million US commuters, or three quarters of the workforce, drove into work alone last year, data released Tuesday by the US Census Bureau showed.

In percentage terms, solo commuters fell slightly from 76.1 percent of the workforce in 2007 to just over 75.5 percent last year, but a head count would have shown there were three million more cars carrying one person into work on US highways last year than in 2007, the data showed.

Carpoolers and users of public transportation both saw increases in number and in percentage of the workforce, but still represented a mere sliver of the commuter pie compared to solo travelers.

Around 11 percent of the US workforce shared a lift to get into work in 2008, up from 10.4 percent in 2007, while 5.0 percent took public transportation last year, not a significant change from the 4.9 percent who did so the previous year, the census data showed.

"It's not that people don't want to change their travel habits, but many people don't have options," said AAA Mid-Atlantic spokesman John Townsend, mid-Atlantic spokesman of the American Automobile Association, an independent, not-for-profit organization for US car drivers.

"There's still the impediment that many rural communities don't have access to mass transit. Until small communities get mass transit, you won't see much of a change in Americans' commuting habits, said Townsend.

That said, last year was a record year for mass transit ridership as people flocked to public transport to beat sky-high petrol prices and the recession, which was starting to bite, said Townsend.

In 2008, Americans took 10.7 billion trips on public transportation, putting ridership at its highest level in 52 years, he said.

Petrol hit an all-time high in the United States in 2008, topping US$4 (S$5.70) a gallon in most states by mid-year.