§ 53-a. Warning signs. Every municipality or political subdivision, or in case of state highways the department of transportation, which is charged with the duty of maintaining a highway at places where such highway crosses a railroad at grade, shall install and maintain an approach warning sign in each such highway on each side of each railroad grade crossing. In case of the failure or refusal of any such municipality or political subdivision or railroad company to install or furnish such signs as herein provided the commissioner of transportation shall take proceedings to compel obedience to the provisions of this section by the municipality or political subdivision or by the railroad company. The supreme court at a special term upon a special proceeding brought by the commissioner of transportation shall have the power in all cases to compel compliance with the provisions of this section subject to appeal to the appellate division of the supreme court and the court of appeals in the same manner and with like effect as is provided in case of appeals from a judgment of the supreme court.

Where physical conditions at any grade crossing are such that the commissioner of transportation deems it impracticable to place such approach warning signs, such commissioner of transportation may by order release the municipality or other political subdivision or the department of transportation from the obligation of installing and maintaining such signs and may by order direct other suitable warning signs to be furnished by the railroad company and installed and maintained by the municipality. The erection and maintenance of any sign or signs other than said approach warning signs may be prohibited by any such municipality, political subdivision or department of transportation in any highway between any such approach warning sign and any such crossing, or in any location where the warning sign may be obscured from view by the presence of such other sign or signs.

The design, location, and manner of installation of such signs shall conform to the manual and specifications for a uniform system of traffic-control devices adopted by the department of transportation.

It shall be the duty of the driver of any vehicle using such street or highway and crossing to reduce speed to a safe limit upon passing such sign and to proceed cautiously and carefully with the vehicle under complete control.

The commissioner of transportation may require the railroad company or municipality or political subdivision which is charged with the duty of maintaining the highway wherever practicable to maintain its property at or near such grade crossing free of obstruction to vision.

Provided, however, any approach warning sign, maintained pursuant to this section, installed prior to the time this act takes effect may continue as and shall be deemed a lawful approach warning sign for the purposes of applying the provisions of this section.