The department may appoint any person in its employ whose special duty it shall be to enforce the statutes and orders promulgated thereunder which prohibit or restrict the passage of vehicles and trailers over ways and bridges, or designated sections thereof, under such conditions or in such manner as may cause undue damage to any such way or bridge. Every such person shall be appointed in writing by the department to serve during its pleasure and shall have the same power as sheriffs and their deputies to arrest and prosecute all persons caught violating said statutes and orders within the territorial limits designated in his appointment. He shall be entitled to the same fees as sheriffs and their deputies for like services.   [PL 1971, c. 593, §22 (AMD).]