CHICAGO - To the six leather-clad Harley riders from Montreal who pulled off the interstate to eat lunch on Wednesday, the open road seems even more open this year.

The dining area was more than half empty, and so were many of the highways on their 1,800-mile trek to and from a motorcycle rally in Sturgis, S.D., this year's destination on their annual U.S. visit.

"There was much less traffic, much less congestion," said Nathalie Miousse, 36. "This was our first time to Sturgis, and they told us it was less crowded than in other years."

Higher prices for gasoline and other necessities are forcing more Americans to downshift on their summer road trips, and everyone from gas station owners to restaurant servers is feeling the pinch.

Americans drove 12.2 billion fewer miles in June than a year ago, the government said Wednesday, down 4.7 percent to 250.2 billion, the lowest for June since 2002 and the biggest monthly drop this year.

Driving on rural interstates fell nearly 7 percent, which is "a pretty good indication that multistate commercial traffic and regional vacation travel are down," said Doug Hecox, a spokesman for the Federal Highway Administration.

Highway officials expected metropolitan areas to show the biggest decline because people have mass transit as an option, but it came in rural areas instead.

"There may be broader economic reasons," Hecox said, including high food prices and a tough job market. "The effects of that may be digging deeper in rural areas," he said. "People in the middle of the country may just be staying home."

For Road Ranger USA, Rockford, Ill., operator of 73 service stations in seven Midwestern states -- most in rural towns and near interstates -- gasoline sales fell 5 percent this year along interstates and urban areas and 15 percent in rural areas such as Freeport, Ill., said Dan Arnold, the company's president.

"We're in the eye of the storm," Arnold said. "Summer travel is down a little bit, but in smaller communities it's down more significantly. They have less disposable income, so higher gas prices affect them disproportionately. It just comes down to having less money to spend, so you stay home."

June was the eighth straight month of decline in driving, and 2008 is on pace to be the first year of decline since 1980. Americans also used 400 million fewer gallons of gas in the first quarter, according to the highway administration.

As car owners think twice about driving, more are taking trains. Amtrak ridership rose 14 percent in July to nearly 2.8 million. Ridership is up 11 percent for the year.

Distributed by McClatchy-Tribune Information Services.