N.Y. Veh. & Traf. Law § 1651

§ 1651. Traffic regulations on county roads outside of cities and\nvillages. The county superintendent of highways of a county may by\norder, rule or regulation designate county roads in such county outside\nof cities and villages as through highways and order traffic signals,\nstop signs, flashing signals or yield signs erected on county roads or\ntown highways at specified entrances to such through highways or\ndesignate any intersection of a county road with another county road or\nwith a town highway as a stop intersection or a yield intersection and\norder like signs or signals at one or more entrances to such\nintersection.\n