Airports in Los Angeles and Philadelphia are among proposed test sites for transportation ID cards that could be issued to travelers, allowing them to pass easily through security checks.

Transportation Security Administration chief James Loy said Tuesday that the cards also would be tested at the ports of Long Beach, Calif., and Wilmington, Del.

Loy said transportation workers would first get the IDs at the ports and at Los Angeles International and Philadelphia International airports. If the cards prove successful, they could be extended to passengers.

"We want to establish those prototypes almost immediately," Loy said, adding that the proposed testing is awaiting congressional approval.

Loy said the ID card technology would form the basis for what he calls a "registered traveler program."

He recently told the Senate Commerce and Transportation Committee that people who register for the program would have to submit to detailed background checks.

"We will know more about them from a security standpoint than anonymous passengers who present themselves to our screeners at the airport," he said.

The program would ease congestion at security checkpoints and reduce security hassles for registered travelers, he said.

"This is great news for passengers," said David Stempler, president of the Air Travelers Association, a passenger advocacy group. "Anything that will speed passengers through airport processing is something that's going to get airline passengers back on the planes again."

But Paul Hudson, executive director of the advocacy group Aviation Consumer Action Project, said Mohammed Atta, the ringleader of the Sept. 11 hijackers, could have become a registered traveler. So could Timothy McVeigh, the Oklahoma City bomber, and Theodore Kaczynski, the Unabomber.

Hudson said he supports identification cards for transportation workers, who number in the hundreds of thousands, but not travelers, who number in the billions.

"There's really no way to prevent smart terrorists from getting these smart cards if it's opened up to the public," Hudson said. "Identity theft and false IDs are a way of life for almost all smart terrorists and criminals."

Robert Johnson, TSA spokesman, said the ID cards would be used in conjunction with an improved passenger screening system that would flag suspicious people before they get on a plane. The current system, called CAPPS for Computer Assisted Passenger Prescreening System, collects information about passengers' travel history from the airlines.

"We don't intend to willingly issue those kinds of cards to those kinds of people, ever," Johnson said.

The program can't get under way until Congress gives the TSA the go-ahead, Johnson said. The Senate Appropriations Committee has held up the program because of concerns that the TSA might choose a technology for the card that's inefficient or too expensive, he said.

"We can begin almost immediately on a project like that once we answer the concerns of Congress," Johnson said.

Congress could approve the program by the end of the year.