Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 160, § 202

A corporation which cannot agree with the postmaster general or other proper officer of the United States as to the compensation to be paid for such transportation may notify the postmaster general of its unwillingness to carry the mails upon the terms proposed; and after the expiration of three months from the depositing of such notice in a post office in the commonwealth, addressed to the postmaster general, such corporation shall be absolved from the duty imposed in the preceding section, unless he or some officer or agent of the post office department within that time has filed a petition in the supreme judicial court in any county, praying for the appointment of three commissioners to fix the price to be paid to the corporation for such service; and the court, after notice to the corporation, shall appoint three commissioners to hear the parties and determine such compensation, the award of a majority of whom, being made to and confirmed by said court, shall be final as to all past service and for a period of two years after such confirmation.