BOSTON (AP) – Dozens of MBTA bus drivers and subway operators have been disciplined for using cell phones while on the job during the past two and a half years.

Records obtained by The Associated Press show that penalties for the Massachusetts Bay Transportation Authority drivers ranged from a day suspension to, in at least one case, the firing of a subway operator.

Use of a cell phone by drivers is considered a safety violation and is strictly prohibited by MBTA employee rules. It can lead to suspension and dismissal in the case of repeated violations.

At least 44 individual drivers have been cited by T officials since January, 2006. About three-quarters of the disciplinary actions involved bus drivers. One of the suspensions was later rescinded.

Drivers can be cited whether the train or bus is in motion or the cell phone is actively being used. Drivers are also barred from using hands-free cell phone devices.

“The MBTA will continue to enforce the policy, and discipline those who violate it,” said MBTA spokesman Joe Pesaturo. “The MBTA takes this matter very seriously.”

Pesaturo also pointed out that the drivers disciplined were a fraction of the 2,200 employed by the transit authority. MBTA bus drivers alone made more than 101 million trips during the last fiscal year, he noted.

MBTA officials say they rely in large part on riders to report any actions of MBTA drivers that they think could be potentially dangerous, including cell phone use.

In just the past 14 months, the T has receive 242 complaints about cell phone use by bus drivers, subway operators, Silver Line drivers and commuter rail operators.

A call to the union representing MBTA drivers was not immediately returned Saturday.

MBTA General Manager Daniel Grabauskas has taken steps to discourage the use of cell phones by drivers.

Those steps include the creation of an agency “hot line” that relatives and friends of T drivers can call in an emergency when they need to contact a driver instead of trying to call them on their personal cell phone.

Besides the use of a cell phone, the agency also bars operators from reading books or magazines, playing the radio, eating, watching portable televisions or listening to iPods or MP3, CD or cassette players while on the job.

The focus on cell phone use by MBTA drivers was prompted by last month’s fatal trolley accident.

Operator Terrese Edmonds, 24, of Boston was killed when her trolley slammed into another slower-moving trolley just outside the Woodlands Station in suburban Newton during the evening commute.

Investigators looking into the crash initially focused on reports from passengers that driver Edmonds, had appeared to be using a cell phone before the accident.

That theory has since been debunked by Middlesex District Attorney Gerry Leone who released a report earlier this month that concluded Edmonds wasn’t talking on her cell phone or sending text messages or e-mails in the moments before the accident.

Leone said there was also no evidence that Edmonds was in the process of using the Internet on her cell phone before the crash.

About a dozen passengers were hurt in the May 28 collision.

The early speculation that Edmonds might have been on her phone prompted Grabauskas to renew a warning to T operators to put down their cell phones.

An investigation to determine the cause of the accident by the National Transportation Safety Board could take 12-18 months to complete.