ยง 231. Where route coincides with another route. 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.
Structure New York Laws
Article 6 - Rapid Transit Act of 1875
220 - Application for Railroad; Commissioners.
221 - Oath and Bond of Commissioners.
222 - First Meeting of Commissioners.
223 - Determination of Necessity of Railroad and Route.
224 - Adoption of Plans, and Terms Upon Which Road Shall Be Built.
225 - Appraisal of Damages and Deposit of Money as Security.
226 - Shall Prepare Certificate of Incorporation; Proviso as to Forfeiture.
228 - Commissioners to Deliver Certificate; Affidavit of Directors.
231 - Where Route Coincides With Another Route.
232 - Commissioners to Transfer Plans.
233 - Commissioners to File Report; Confirmation Thereof.
235 - Quorum; Term of Office; Removal; Vacancies in Board of Commissioners.
236 - Abandonment or Change of Route; New Commissioners; Their Powers and Proceedings.
237 - Abandonment of Portion of Route by Elevated Railroad.
238 - Increased Deposit, When and How Required.
239 - Trains to Come to Full Stop.
240 - Gates or Vestibule Doors.
241 - Penalty for Violation of Two Preceding Sections.
242 - Sections to Be Printed and Posted.
244 - Lighting Cars on Elevated Railroads in Cities of Over Twelve Hundred Thousand Inhabitants.