No town, city or borough, nor any board or officer thereof, shall make any ordinance respecting the regulation, use, lighting or other equipment of motor vehicles, or respecting the use of equipment or accessories upon the same; but any ordinance in force in any town, city or borough in respect to maintaining public service vehicles in a sanitary condition shall remain in force, and authority given to any town, city or borough, or to any board or officer thereof, to regulate shows, processions, assemblages, traffic or parades in streets and public places and to regulate the use of public parks, and ordinances enacted in pursuance of such authority, shall remain in force, and authorities of any town, city or borough shall have power to establish and enforce ordinances fixing traffic routes and public stands for public service vehicles and traffic rules for all vehicles.