540 CMR 21.00 is adopted by the Registrar of Motor Vehicles, pursuant to M.G.L. c. 90, §§ 7A and 31, to establish rules and regulations for the semiannual safety inspection of school pupil transportation vehicles under M.G.L. c. 90, § 7D, (7D vehicle) to be performed by licensed Safety Inspection Stations.
540 CMR, § 21.01