Riders on certain Metropolitan Transportation Authority buses and subways may soon notice an increased security presence, for the mutual benefit of riders and the agency.

Agency officials said on Monday that they would expand an initiative aimed at uncovering fare beaters on local bus routes; the initiative had been limited to Select Bus Service routes, where riders must pay before boarding. Violators will be issued fines of $100 by members of “Eagle teams,” which are staffed largely by retired law enforcement workers.

The authority has estimated that around $100 million is lost annually to fare evasion on subways and buses, with more than half of the total coming from buses. Last month, the police said they had arrested more than 1,200 fare evaders on buses in 2012, more than double the number at the same point last year.

“Those of us who believe emphatically in the broken windows theory feel that when they go after the little things like fare evasion, big things are also taken care of,” said Vincent DeMarino, the vice president for security at New York City Transit.

He noted that some Select Bus routes had lower incidences of assaults on bus drivers.

The transportation authority also said Monday that additional police officers had been placed on subways in the Bronx and Queens in response to crime trends on the transit system.

From midnight to 6 a.m. on weekends, an officer has been stationed on every train in the Bronx and two lines in Queens: the No. 7 train and the A train.

“This strategy has proven to be effective and will be continued,” Joseph Fox, the chief of the Police Department’s transit bureau, said Monday to a transportation authority committee meeting.