NOGALES, Ariz. — U.S. officials want to see if the same technology that speeds cars through highway tollbooths and identifies lost pets can unclog border crossings without compromising security.

Homeland Security Undersecretary Asa Hutchinson announced yesterday that the government will begin testing radio-frequency identification (RFID) technology at this crossing and three others — including two in Washington state — by midsummer.

Weeding out potential terrorists, drug dealers and other criminals from shoppers, truckers and tourists who regularly pass through border crossings takes time. The RFID technology is designed to reduce the wait while giving authorities more information on who is coming into the country and who is leaving.

"We do not keep track of who enters this country," Hutchinson said while standing in an inspection booth at a crossing that is used each year by 5.4 million pedestrians and 3.9 million vehicles. "We need to have a comprehensive system, and that's what our pilot [test] will do."

Currently, foreign visitors at the 50 busiest land border crossings in 10 states are fingerprinted as part of the government's new screening system. The system, called US-VISIT, scans photographs of the visitor's face and index-finger prints into a computer, which are matched with federal agencies' criminal databases.

With RFID technology, people or objects are identified automatically and swiftly. That allows vehicles outfitted with the technology to zip through toll plazas without stopping. At the border, people and vehicles still will have to stop, but if their identifying data produce no red flags, they will get just a cursory check rather than lengthy questioning.

The chip with the identifying information would be placed in a document, such as the State Department-issued border crossing cards for those who regularly make short trips across the Mexican border.

The chip is attached to an antenna that transmits a signal to a handheld or stationary reader, which converts the radio waves from the RFID tag into a code that links to identifying biometrical information in a computer database read by border agents.

The technology — with some variations — has been in use for years in systems for toll collection, equipment tracking, merchandise tags and pet identification. Unlike bar codes, the RFID chip doesn't need to be oriented before a scanner for reading but need only be within transmission range, or 18 to 30 feet in this case.

Jay Stanley, spokesman for the American Civil Liberties Union, said he is concerned the technology will infringe on privacy rights.

"It permits automatic invisible ID checks by the government," he said.

But Nogales Mayor Albert Kramer said such a system is needed to make the clogged border system more efficient. "Any improvement is welcome," he said.

Officials said that by July 31, testing is expected to be under way in Nogales; Alexandria Bay, N.Y.; and the Pacific Highway (often used by truck traffic) and Peace Arch in Washington state. Tests are expected to last through spring of next year.