N.Y.C. Admin. Code § 19-148: § 19-148 Safeguards against collision with posts, pillars and columns in streets.

a. Every post, pillar or supporting column of a superstructure, including supporting columns of railroad structures, located at such points in the roadways of streets as to constitute a menace to vehicular traffic turning or going into the part of the street at or near the point of such location, shall be striped from its base to a point at least twelve feet high with reflectors or reflectorized lights, in such manner as shall be determined by the commissioner. At night, where directed by the commissioner, there shall be displayed a light of sufficient illuminating power to be visible at a distance of two hundred feet, on an arm or bracket extending from such post, pillar or supporting column, or suspended from the superstructure. The striping and lighting of such posts, pillars or supporting columns covered by this section shall be maintained to the satisfaction of the commissioner.

b. The commissioner shall have power to direct an order to the owner or operator of a superstructure requiring compliance with the provisions of this section.