WESTPORT — Some school buses in town will begin using cameras to catch drivers that don’t stop for the bus as children climb on and off.

Approved on a trial basis, if the test run catches enough drivers breaking traffic laws by passing the buses, cameras will be installed across the school district’s fleet.

The Board of Education approved the addition Jan. 30, a move that will come at no up-front cost to the town. Instead, Redflex — the company that offers the Student Guardian technology and support — is compensated through a share of penalty fees from drivers caught using the program.

Two cameras will be installed on the front and back of each trial bus on the driver’s side. The cameras begin monitoring when the bus’s stop sign is out and flashing, when children are getting on and off. If a car or truck passes the bus, the camera is triggered to take photos and video, which is then sent to police who review the images and determine whether to issue a ticket. If officers choose to mail the driver an infraction, Reflex passes its evidence along to the courts.

Town police — necessary for enforcement — are supportive of the measure.

Sandra Evangelista, the Westport schools’ transportation coordinator, told the board how Student Guardian has functioned in nearby towns. New Canaan piloted the program but saw “very, very low” infraction rates, she said, so camera use halted when the two equipped buses went out of service. Norwalk, whose school board adopted bus cameras a year and a half ago, saw a delay as enforcement wrinkles were worked out with a prosecutor. But the cameras went into use at the beginning of this school year, Evangelista added.

Milford, as she described, began using Student Guardian’s services two years ago when the town government entered into a contract and has found the program to require little use of police resources.

Some board members spoke of the initiative as a deterrent before its unanimous approval.

“I just think prevention is so key to this, and that’s what I really like about it,” Karen Kleine said.

Redflex Student Guardian can now move forward with its route analysis on Westport buses, and if passing incidents per bus per day meet the company’s threshold, the board will enter negotiations to fully implement the cameras.

“I think we all know anecdoteally about incidents,” Chair Michael Gordon said just before the vote, “and I would want to limit the barriers to getting this done as quickly as possible.”

lweiss@hearstmediact.com; @LauraEWeiss16