Mass. Gen. Laws ch. 71 § 48A
School committees shall have authority to organize school safety patrols, consisting of pupils, whose functions shall be to encourage pupils to cross highways at designated crossings and when conditions are safe, to assist drivers of school buses in maintaining safety rules and to protect pupils who are boarding or alighting from such buses; and may adopt regulations relative to the flagging or signalling of school buses by members of said safety patrols. Said committees may make expenditures, from funds appropriated for school purposes, for the purchase of traffic belts, so called, to be used by the safety patrol leaders in safeguarding the passage of pupils to and from school. Nothing herein contained shall authorize a safety patrol member to direct vehicular traffic, provided, however, that such patrol member may use a flag or other approved signal to indicate to a driver that school children are crossing or are about to cross the street. No patrol member shall be stationed in that portion of the highway intended for the use of vehicular traffic, but shall perform his duties from the curb and sidewalk areas.
No liability shall attach either to the school committees or any individual member thereof, a superintendent, teacher, patrol member, or parent of a patrol member, or other school authority by virtue of the organization, maintenance or operation of a safety patrol under authority of this section.
Mass. Gen. Laws ch. 71, § 48A