Half the MTA Maryland fleet of buses will be equipped with audio recording equipment by the end of the year. (MTA photo)

(Elliott Francis and Marti Johnson - Washington, D.C., WAMU) The Maryland Transit Administration is recording conversations between bus drivers and passengers, which is prompting critics to peg the audio recordings as violations of privacy.

The MTA began recording audio on 10 buses in Baltimore this week, with plans to expand to half the fleet by next summer. The agency runs local buses in the Baltimore-Washington area with commuter routes serving outlying communities. The buses are already equipped with video cameras that sport microphones — they just have to be switched on.

The state attorney general's office says the addition of audio doesn't violate Maryland's wiretapping law, but attorneys with the American Civil Liberties Union say bus riders shouldn't have to sacrifice their privacy rights.

The audio recordings are an attempt to increase commuter safety, says MTA information officer Terry Owens.

"We were convinced that this additional tool would help us better safeguard our system, so we have this system in place on ten of our buses, testing the technology to make sure it's effective," he says.

There are signs on the buses letting riders know they're being recorded. But the American Civil Liberties Union staff attorney David Rocah says recording the conversations violates riders privacy rights.

"I don't think public transit riders should have to give their legitimate expectation of privacy and their ability to have a private conversation as a condition of riding a bus," Rocah says.

MTA says the state attorney general's office says that there is no legal expectation of privacy on public buses, but some state legislators are ready to take up the issue in the next general Assembly, the ACLU says. State Sen. Brian Frosh says the General Assembly will most likely set standards for oversight and accountability.