Mass. Gen. Laws ch. 160 § 70A
A railroad corporation may acquire, hold, maintain and operate steamship companies, ferries, ferry boats and docks, and either directly or through subsidiaries, may own, maintain and operate motor vehicles not running upon rails or tracks, and aircraft for the transportation of passengers and/or freight. A railroad corporation, or any subsidiary thereof, in maintaining and operating such vehicles, shall be subject to all provisions of chapter ninety and of chapter one hundred and fifty-nine B and to all other laws applicable to aircraft or motor vehicles and the operation thereof, and, in respect to the transportation of passengers, to chapter one hundred and fifty-nine A, but in respect to the transportation of freight shall not be subject to the provisions of chapter one hundred and fifty-nine.
The department may from time to time prescribe forms of accounting reports relating to the operations of motor vehicles for the transportation of passengers or freight by a railroad or subsidiary thereof and such reports shall be made in accordance with the forms prescribed.
Motor vehicles operated by a railroad corporation directly or through subsidiaries for the transportation of freight within the commonwealth shall be operated only in areas now served by such corporation; and the department shall have authority, after a hearing had upon its own motion or upon complaint, to determine specified areas in which or points between which such motor vehicles may be operated and by order to prescribe and limit the number of such vehicles that may be operated by a railroad in such areas or between such points and to regulate the operation of such motor vehicles.
This section shall not be construed to affect any right or privilege derived from the constitution or laws of the United States.
Mass. Gen. Laws ch. 160, § 70A