N.Y. R.R. Law § 231
Whenever the route or routes determined upon by the commissioners coincide with the route or routes covered by the charter of an existing corporation, formed for the purpose of constructing and operating such a railroad, and it has not forfeited its charter or failed to comply with the provisions thereof, requiring the construction of a road or roads within the time therein prescribed, such corporation shall have the like power to construct and operate such railroad upon the fulfillment of the like requirements and conditions imposed by the commissioners as a corporation specially formed under this article, and the commissioners may fix and determine the route or routes by which any elevated steam railroad now in actual operation may connect with other steam railroads or the depots thereof, or with steam ferries, upon making compensation therefor, and in case such corporations can not agree with the owners of such steam railroads, depots or ferries upon the amount of such compensation, and such owners may be entitled to compensation therefor, the amount of such compensation shall be ascertained and paid in the manner prescribed in the condemnation law, and upon fulfillment by such elevated railroad corporation, so far as it relates to such connection, of the requirements and conditions imposed by this article, it shall possess all the powers conferred by section two hundred and twenty-nine of this article, and when any connecting route or routes shall be so designated, such elevated railroad corporation may construct such connection with all the rights and with like effect as though the same had been part of the original route of such railroad.
N.Y. R.R. Law § 231