DETROIT (WWJ) - Drivers are getting an unwelcome surprise at the pump this morning -- $4-a-gallon gas at many stations.

WWJ's Ron Dewey -- doing an informal survey along Telegraph -- found gas averaging $3.99 a gallon, cash only. A BP station at Telegraph and Wick was selling gas at $3.89 a gallon. There were a few stations with prices north of that fateful $4 mark, but Ron said what was telling was what people were doing at the pump. They were no longer filling up. He found people pumping $40, $20, $10, even $5 at one pump.

Detroiter David Harrison understands why. He ditched his V-8 pickup for a 4-cylinder compact, but still only put a $10 bill in the tank.

"I get back and forth to work pretty easy cause of that," Harrison said. "I just try to make it -- like everybody else."

Prices could go even higher this summer -- at least until the federal government and Enbridge can agree on reopening a pipeline from Canada to Chicago that shut down after an oil spill in Wisconsin.