A customer fills a car's tank at a gas station approximately one mile from the White House in Washington March 11, 2008. REUTERS/Larry Downing

WASHINGTON (Reuters) - As gasoline prices broke records in 2007, Americans cut back on their driving for the first time in more than 20 years, according to the U.S. Federal Highway Administration.

Total travel fell 0.4 percent to 3.00 trillion miles from 3.01 trillion miles in 2006.

In December, when U.S. retail gasoline averaged $3.02 a gallon, travel fell 3.9 percent to 236.6 billion miles from 246.3 billion miles in 2006.

With gasoline prices still climbing, other data shows Americans are responding by changing their gas-guzzling habits. Not only are they driving less, but they are buying more fuel-efficient vehicles and utilizing more public transportation. Daily ridership on U.S. subways and public buses is at the highest level in more than 50 years.