Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 90, § 3A

The acceptance by a person who is a resident of any other state or country of the rights and privileges conferred by section three, as evidenced by the operation, by himself or agent, of a motor vehicle or trailer thereunder, or the operation by such a person, by himself or his agent, of a motor vehicle or trailer on a way, or private way if entrance thereto was made from a way, or in any place to which the public has a right of access, in this commonwealth otherwise than under said section, shall be deemed equivalent to an appointment by him of the registrar, or his successor in office, to be his true and lawful attorney upon whom may be served all lawful processes in any action or proceeding against him or his executor or administrator, growing out of any accident or collision in which such person or his agent may be involved while operating a motor vehicle or trailer on such way or in such place, and said acceptance or operation shall be a signification of his agreement that any such process against him, or his executor or administrator, which is so served shall be of the same legal force and validity as if served on him personally. This section shall not authorize the service of process upon any person who has executed a power of attorney under section three D, or upon any foreign corporation which has executed a power of attorney under section three of chapter one hundred and eighty-one.