N.Y. R.R. Law § 187
Any street surface railroad corporation which had prior to the tenth day of May, eighteen hundred and ninety-three, constructed and was on that date operating any extension or branch of its railroad along any streets or highways or portion thereof in a city having less than fifty thousand inhabitants, or in any town adjoining such city, and which had prior to said date obtained consent of the owners of one-half in value of the property bounded on, and the consents also of the local authorities having control of that portion of the streets, roads or highways upon which such extension or branch was constructed and being operated to the construction and operation of the same, is hereby authorized to operate and maintain any such branch or extension, upon filing in the office of the secretary of state a certificate, signed by its board of directors, which certificate shall contain a statement of the names of the cities, towns, villages and counties, and the names or description of the streets, avenues and highways in which such extensions or branches have been constructed, the places from and to which the same have been constructed, and are to be maintained and operated and the length thereof, as near as may be; thereupon said extensions and branches shall be deemed and considered a part of the lines of said railroad from the date of the filing thereof, and all corporate action relating to the construction, maintenance and operation of such extensions or branches, or creating liens upon the same by said corporation, are hereby validated and confirmed. Nothing in this section contained shall affect or impair any vested right or any litigation pending on said tenth day of May, eighteen hundred and ninety-three, nor shall any corporation which shall avail itself of the provisions of this section be deemed thereby to have waived any rights which it therefore had to maintain and operate any branches or extension named in any certificate filed by it hereunder.
N.Y. R.R. Law § 187