He was hanging out on a recent Friday night at a Starbucks with a group of his friends, and all of them said the price of gasoline, made worse by difficulty in finding summer jobs, was cramping their style.

“I used to drive around and hang out here with my friends five nights a week last summer, but I just can’t afford to buy gas anymore,” said Elliot Lee, 19, another engineering student. Mr. Lee said that since arriving home in East Dundee, Ill., for the summer, he had withdrawn $100 from his savings account to pay for gasoline.

Perhaps the summer’s most visible change is occurring in the downtown strips of small towns where, for decades, cruising on Friday and Saturday nights has been a teenage rite of passage. It is a peculiarly American phenomenon  driving around in a big loop, listening to music, waving at one another and wasting gasoline.

“We’re not cruising around anymore, with gas costing $4.50 a gallon,” said Ewelina Smosna, a recent graduate of Taft High School in Chicago, as she hung out the other night at the Streets of Woodfield, an outdoor mall in Schaumburg. “We just park the car and walk around.”

According to police officers in towns like Elkhart, Ind.; Grand Haven, Mich.; and Mount Pleasant, S.C., traffic has dropped markedly on cruise nights.

“Teen cruising is way down from 2005, when it used to be bumper to bumper downtown,” said David Scott, a senior officer in Grand Haven, a popular resort town hugging the Lake Michigan shoreline. “Traffic downtown used to be so bad in the summer, you couldn’t drive faster than 10 miles an hour. Last Friday night, I didn’t even have to wait in line to get through a light.”