WASHINGTON — Americans are clearly opting for 'staycations' this summer, and the federal government has the stats to prove it. The U.S. Department of Transportation on Wednesday said that Americans drove 12.2 billion fewer miles in June than the same month a year earlier, the biggest monthly driving drop in a downward trend that began in November.

The 'trend signals an urgent need for new highway financing,' the U.S. Department of Transportation said in a statement. 'We can't afford to continue pinning our transportation network's future to the gas tax,' said U.S. Transportation Secretary Mary E. Peters. 'Advances in higher fuel-efficiency vehicles and alternative fuels are making the gas tax an even less sustainable support for funding roads, bridges and transit systems.'

However, some observers expect that the recent drop in gas prices to below $4 a gallon in many parts of the country will prompt drivers to hit the road again. The current average price for a gallon of regular unleaded gas is $3.77, according to AAA's Fuel Gauge Report on Thursday morning.

The federal government said that Americans drove 53.2 billion fewer miles in November through June than they did over the same period a year earlier. That's a bigger drop than the 49.3 billion fewer miles driven by Americans over the entire decade of the 1970s, a period known for oil embargoes and gas lines.