The board of aldermen or the selectmen may, subject to the approval, revision or alteration of the department, establish such regulations as to the rate of speed, the manner and extent of use of tracks, and the number and routes of cars which run over such tracks, within their city or town, as public interest and convenience require; and a street railway company whose servants or agents wilfully or negligently violate any such regulations shall forfeit not more than five hundred dollars.
Massachusetts Legal Code