Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 160, § 186

A railroad corporation may establish for its sole benefit fares, tolls and charges upon all passengers and property conveyed or transported on its railroad, at such rates as may be determined by its directors, and may from time to time by its directors regulate the use of its railroad; but such fares, tolls and charges, and such regulations, shall be subject to revision and alteration by the general court, or by such officers or persons as it may appoint for the purpose, anything in the charter of the railroad corporation to the contrary notwithstanding.