No person other than an employee in the service of the commonwealth or any political subdivision thereof or an employee in the service of an independent contractor acting for the commonwealth or any such subdivision shall pile, push or plow snow or ice onto a state highway so as to impede the flow of traffic on such way. Whoever violates this section shall be punished by a fine of not more than one hundred and fifty dollars.
Mass. Gen. Laws ch. 85, § 7B