On buses, cameras are watching and listening The Maryland Transit Administration began audio recording in October on some buses in and around Baltimore and hopes to expand that to about half of the agency's 700 buses by summer. In San Francisco, buses and trains have both audio and video recording, with the audio devices always running. And in Atlanta, transit officials are adding video and audio recording to buses and will put them on trains next. The stated intention of the systems on the nearly 300 Ride On buses with audio recording is to capture what drivers say. But the systems, which are always recording, are capable of picking up conversations of people sitting or standing near the drivers. A passenger talking to a spouse or child could end up being recorded, the snippet saved for several days on the system's hard drive. Some privacy experts say audio recording devices such as those on Ride On raise serious concerns. Millions of commuters in the region board buses each year for the thousands of daily runs on the hundreds of routes snaking through the area. George Washington University law professor Daniel J. Solove, author of "Understanding Privacy," said recording a person during one commute might not seem particularly invasive. But with daily monitoring, "the totality of surveillance" can really add up, he said. "Privacy is like that," Solove said. One camera on a bus, okay. But a camera here, a camera there, a camera everywhere, is much different. From body scans and pat-downs at airports to bag searches at subway stations, most Americans have come to accept less privacy while traveling since the Sept. 11 terrorist attacks ushered in a new era of transportation security. Ubiquitous eyes Video recording has been a part of public transit for decades and is now common on buses and trains and at stations. The 2005 terrorist attacks on the London subway were a "watershed moment" for this technology, because investigators used surveillance videos to quickly highlight images of the suspects, said Greg Hull, director of security and operations for the American Public Transportation Association, a nonprofit international industry group. Metro has 4,400 cameras scattered through its rail system, peering at fare machines, platforms, mezzanines and other spots at all 86 stations. Each Metrobus is equipped with multiple cameras. One is a driver-specific camera that can retain video and audio, but only when triggered to do so by a crash, sudden movement or the driver pressing a button. Known as DriveCam devices, these cameras also are used on the District's Circulator buses, TheBus in Prince George's County and OmniRide in Prince William County. The cameras are constantly recording, but clips are almost immediately recorded over; only when triggered does the system begin saving the recorded clips.