N.Y. Veh. & Traf. Law § 1684

§ 1684. State highways maintained by the state. No local authority\nshall place or maintain any traffic-control device on any state highway\nmaintained by the state, or at any location so as to prohibit, restrict\nor limit the movement of traffic proceeding along, entering or crossing\nsuch highway, nor shall any ordinance, rule or regulation affecting\ntraffic or stopping, standing or parking on state highways maintained by\nthe state be effective unless or until approval in writing has been\nobtained from the department of transportation, and the department of\ntransportation may at any time rescind or modify such approval.\n