N.Y. High. Law § 104
If it shall appear necessary to close any state highway in an emergency or in order to permit a proper completion of any work of improvement thereon, the commissioner of transportation or the county superintendent upon the request of the commissioner of transportation, shall execute a certificate and file the same in the office of the town clerk of the town in which such highway is situated. If it shall appear necessary to a county superintendent to close a county road or a town superintendent to close a town highway, said superintendent shall execute a similar certificate and file the same in the office of the town clerk in which such highway is situated. In either case, such certificate shall state the necessity for the closing of such highway and describe the portion thereof to be closed. At the time of filing such certificate the commissioner of transportation or the county superintendent, as the case may be, shall notify the contractor who is constructing, improving or repairing said state highway that the same is closed to public travel until otherwise notified and shall cause to be posted conspicuous notices to the effect that the highway is closed.
It shall thereupon be the duty of said contractor to erect suitable obstruction for closing said state highway, including the necessary lights which shall be visible to any one approaching such obstruction from one hour after sunset to one hour before sunrise and said contractor shall notwithstanding any general or special law be liable for all damages to persons or property sustained by reason of not so erecting and so lighting such suitable obstruction. If the work of improvement, construction or repairs upon a state highway is being performed by state forces, or otherwise than by contract, the representative of the department of transportation in charge of such work, shall at the time of the filing of such certificate, post conspicuous notices to the effect that the highway is closed, and shall erect and maintain a lighted obstruction in the same manner as hereinbefore described. At the time of filing such a certificate relating to a county road by the county superintendent, he shall notify the town superintendent to close said county road. Upon such notification or upon filing such certificate for closing of a town highway, the town superintendent shall thereupon close the same to public travel by posting conspicuous notices to the effect that the highway is closed and by erecting and maintaining a lighted obstruction in the manner hereinbefore described. In case of the closing of any highway under the provisions of this section, the town superintendent shall, if practicable, provide a new location for, and construct a temporary highway to be used by the traveling public in lieu of the closed highway and may erect temporary bridges when necessary or cause other existing highways to be used. For the purpose of locating, constructing and erecting such temporary highway or bridge the town superintendent may enter upon the lands adjoining or near to the closed highway and may, with the approval of the town board, agree with the owners of such land as to the damages if any caused thereby.
If the town superintendent is unable to agree with such owner upon the amount of damages thus sustained the amount thereof shall be ascertained, determined and paid as provided in section one hundred forty-eight. When such highway shall have been closed to the public as provided herein, any person who disregards the obstruction and notice, and drives, rides or walks over the portion of the highway so closed shall be guilty of a misdemeanor.
N.Y. High. Law § 104