Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 160, § 139

The department, upon petition, and after notice to the railroad corporation and a public hearing, may, for good cause shown, recommend to such railroad corporation such changes as it considers proper in the manner of making up and shifting freight trains or freight cars, and of sounding of whistles on locomotives, and it may by written order forbid or regulate the sounding of whistles on the locomotives of such corporation at any specified grade crossings of the tracks of such corporation with any public way. The corporation which is subject to such order shall, until the order has been modified or annulled by the department, conform in all respects to the terms thereof.