The Philadelphia Parking Authority approved a new 50-cent fuel surcharge on cab fares today in response to drivers' pleas amid rising gas prices.

That means a trip today that begins at the standard $2.70 becomes $3.20 on Monday, following the Parking Authority board of directors' unanimous decision.

And that's not all.

Also Monday, under a surcharge previously approved, each additional passenger will cost another $1, beginning with the second passenger in a taxi.

Thus a three-passenger trip will cost $5.20 before anyone gets in the cab.

That might not even be enough to keep up, said Muhammad Chughtai, president of the Brotherhood of Unified Taxi Drivers. Chughtai asked the Parking Authority, which regulates taxicabs, to authorize a full dollar surcharge, instead of 50 cents, for trips to and from the airport. The board agreed to consider the request in committee.

"Fifty cents is not bad - we don't want to hurt the customers," said Chughtai. "If we ask for too much money, we're going to lose business."

Chughtai said most drivers use premium fuel because, while it is more expensive, it will prolong the life of a vehicle. Price for premium is between $4.19 and $4.30 a gallon, he said.

The fuel surcharge is the first since October 2005, when the Parking Authority authorized a 40-cent increase, which is now part of the base fare of $2.70.