WAITING IN LINE WAITING IN LINE How Bluetooth can measure airport security wait times: 1. Passenger enters security line with personal electronic device. 2. Bluetooth receiver picks up signal from the device and records the time. 3. Passenger exits security checkpoint. 4. A second Bluetooth receiver records exit time from the same device and calculates the time elapsed between the first and second measurements. Source: Darcy Bullock, Purdue University WASHINGTON  Today's smartphones and PDAs could have a new use in the nation's airports: helping passengers avoid long lines at security checkpoints. The Transportation Security Administration is looking at installing devices in airports that home in and detect personal electronic equipment. The aim is to track how long people are stuck in security lines. Information about wait times could then be posted on websites and in airports across the country. "This technology will produce valuable data that can be used in a variety of ways," TSA spokeswoman Lauren Gaches said, noting it could help prevent checkpoint snarls. But civil-liberties experts worry that such a system enables the government to track people's whereabouts. "It's serious business when the government begins to get near people's personal-communication devices," said American Civil Liberties Union privacy expert Jay Stanley. SHOES ON: New scanners could speed up security lines BODY SCANNERS: Headed to 11 major airports The TSA is in the early phases of exploring the technology, which Purdue University researchers tested for a month last year at Indianapolis International Airport. Thumbnail-size receivers near checkpoints detected serial numbers emitted by some electronic devices being carried by passengers. The receivers recorded the time when a passenger entered a security line and the time when the same passenger cleared the checkpoint, Purdue transportation engineer Darcy Bullock said. Only part of each serial number was recorded, and the numbers were quickly deleted, he said. Some electronic devices automatically broadcast, or "chirp," their serial number every 15-20 seconds when they are turned on. People can set their devices so they don't broadcast. Bullock found he could detect signals from 6% to 10% of Indianapolis passengers. "We sit there and listen, capturing the unique identifier," Bullock said. Marc Rotenberg of the Electronic Privacy Information Center said Bullock's current system minimizes privacy risk by recording partial serial numbers. But he worries that could change. Airports Council International security chief Christopher Bidwell said wait-time information would remove some uncertainty of air travel "especially if that information is real-time, up-to-date and accurate." A few European airports have started using such systems, the TSA said. London's Heathrow Airport is working with airlines to start using the technology, airport spokeswoman Mary Kearney said. The TSA used to post information on its website that listed average wait times during the previous month. Measurements were done with time-stamped cards that screeners handed passengers as they entered and cleared a checkpoint. The TSA stopped those measurements in 2008 to focus more on security. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more