Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 160, § 246

If the consent of the department is required for the crossing of a way or traveled place by a railroad for private use, it may limit the number of tracks, and may impose other conditions relative to the use of the crossing by said railroad, and may modify such limitations and conditions.  The department may, upon the complaint of any party interested, or upon its own motion, exercise supervisory powers over all railroads for private use with regard to the character and condition of the roadbed, tracks, crossings, rolling stock, machinery, equipment and appliances used in or in connection with the operation of such railroads, so far as is reasonable and expedient to promote the security of persons employed in the maintenance and operation of the same and of the public.