Phoenix ? The operator of a closed pipeline that normally supplies a third of the Phoenix area’s gasoline got permission Tuesday to begin safety tests, meaning the line could be back in service by the weekend, officials said.

The federal Transportation Department authorized Houston-based Kinder Morgan Energy Partners to begin testing immediately. The line ruptured on July 30 near Tucson and was shut down Aug. 8 as other safety concerns surfaced, leaving many gas stations dry since Sunday.

Motorists have been forced to drive from station to station looking for gas and to wait in lines stretching for blocks in this sprawling city with little mass transportation.

Testing on the pipeline running between Tucson and Phoenix was scheduled to begin Tuesday night, said Rick Rainey, a Kinder Morgan spokesman.

There are no gasoline refineries in Arizona so fuel must be delivered through two pipelines operated by Kinder Morgan, including a second one from California, which is still operational.

Prices rose 10 cents at some stations overnight, said Kim Pappas-Miller, a spokeswoman for AAA Arizona, on Tuesday. One station near downtown Phoenix was charging $3.89 a gallon; $2 a gallon prices were common elsewhere in the city.

Byron Woodson was among nearly a dozen drivers who crowded around the islands of a gas station Tuesday, three hours before gasoline was expected to arrive.

With an empty tank, Woodson could only leave a message with his employer saying he’d likely be several hours late.

“That’s what I was freaking out about,” said Woodson, an administration manager. “Do I have a job?”

A broken gas line from Texas to Phoenix has caused gas prices to skyrocket and lines to form at gas pumps in Phoenix. Phoenix-bound gas tankers, able to carry 8,800 gallons of gasoline, waited Monday to fill up at Kinder Morgan Energy Partners in Tucson, Ariz.