Section 1680 - Department of transportation to maintain a manual of uniform traffic-control devices(a) The department of transportation shall maintain a manual and specifications for a uniform system of traffic-control devices consistent with the provisions of this chapter for use upon highways within this state. Such uniform system shall correlate with and so far as practicable conform to nationally accepted standards. To the extent that the National Manual on Uniform Traffic Control Devices (hereinafter referred to in this section as MUTCD), promulgated by the Federal Highway Administration pursuant to subpart F of part 655 of Title 23 of the Code of Federal Regulations and subject to a public comment period under federal law, does not conflict with the provisions of this chapter and the provisions of other laws of the state, the National MUTCD shall constitute such state manual and specifications; provided, however, such manual and specifications may be modified by the commissioner of transportation by the adoption of a supplement or supplements as such commissioner of transportation determines warranted and in compliance with the applicable provisions of the state administrative procedure act. The manual and its specifications is adopted as the state standard for traffic control devices on any street, highway, or bicycle path open to public travel. No person shall install or maintain in any area of private property used by the public any sign, signal, marking or other device intended to regulate, warn or guide traffic unless it conforms with the state manual and specifications maintained under this section. Unless otherwise provided for by the adoption of a supplement by the commissioner of transportation, the operational practices related to emergency incident responses provided in the manual shall apply to police officers and other emergency responders responding to an emergency only in so far as such officers or emergency responders deem compliance with the manual practicable.(b) No provision of this chapter shall be deemed to require that such manual contain authority for the future installation of any specific kind or type of traffic-control device or combination of traffic-control devices which in the judgment of the department of transportation does not conform to such nationally accepted standards.(c) No state or local authority shall hereafter fabricate or purchase any traffic-control device that does not conform to the current manual and specifications as amended from time to time. No state or local authority shall hereafter install any traffic-control device that does not conform to the current manual and specifications as amended from time to time, except that devices that are on order or on hand and serviceable or operable may be installed and used until the phase-in compliance date specified in the MUTCD. No state or local authority shall continue to use any traffic-control device that does not conform to the current manual and specifications as amended from time to time beyond the phase-in compliance date specified in the MUTCD, except that a city having a population in excess of one million shall conform to the state manual and specifications only insofar as such local authority in its discretion deems practicable.(d) No person, firm, association or corporation shall sell, lease, or offer for sale or hire for use in this state any traffic control device that does not conform to the current manual and specifications as amended from time to time, or unless a certificate of approval has been issued by the commissioner of transportation pursuant to the provisions of section five hundred ninety-nine-b of the general business law. The provisions of this subdivision shall not apply to the sale, lease or offer for sale or hire to a city having a population in excess of one million.N.Y. Veh. and Traf. Law § 1680