What lies ahead for airport security this year

The TSA's goal is to lift the restrictions on carrying liquids, aerosols, and gels aboard aircraft. Toward that end, the TSA has been rolling out new luggage screening machines that can tell the difference between a harmless drink and a deadly explosive. Already, about 500 of these AT X-ray machines have been installed. That number should be doubled by year-end.

By fall 2009, the TSA hopes to get rid of its rule that you must carry all of your liquids in a single clear bag. For a brief period, you'll probably still have to place all of your liquids in a plastic bin separate from your laptop and carry-on bag when passing through airport screening machines.

By next winter, the TSA hopes to lift its size restrictions on liquids, which now limit the carry-on size to 3.4 liquid ounces. The timetable depends on how quickly software updates can be installed on all of the machines and how quickly TSA agents can be trained to use the machines correctly. Officials with the British counterpart to the TSA, the transport ministry, have made a similar pledge.

Another change is to move the baggage screening machines from airport terminals, where they clutter the floor, and put them off-site. So-called "in-line" machines at the Las Vegas and Atlanta Hartsfield-Jackson airports can test bags for explosives without requiring the physical handling of each bag. Las Vegas airport, for once, has embraced the change because it can use the freed-up terminal space to add more slot machines for waiting passengers to use. (For a video explanation of the new baggage inspection system, see below.)

A related change is to replace metal detectors with whole-body image scanners. This will add additional security, says the agency.

In other news: This summer, online travel agencies, such as Expedia, and the online ticketing sites of major airlines will all require you to submit your birth date and gender when buying plane tickets. This is another measure to help identify passengers correctly.

The TSA continues to test improved airport security procedures at Baltimore Washington International airport's terminal B (for primarily Southwest Airlines customers). If popular, the methods tested at BWI airport will be adopted elsewhere in the country. One of the interesting techniques is that the TSA officials are all equipped with wireless walkie-talkies and earpieces, like store clerks in some department stores and restaurants now have, to communicate with each other without having to shout loudly. Surveys have shown that passengers get stressed out by the noise of barking TSA officials, and travelers who have passed through BWI's terminal B say they appreciate its relative quiet. The airport has also introduced "soothing" ambient music and "mood" lighting to make the process feel less stressful. For details, visit the TSA's Checkpoint Evolution online tour of the security checkpoint.

Small airports may not see the technology rolled out as quickly as major airports, and hand-held liquids scanners may be around for some time.

Here's a video explanation of the in-line luggage screening system: