law: 4. Previous sanction of the Central Government required for the opening of metro railway.
  (1)  No metro railway shall be opened for the public carriage of passengers except with the previous sanction of the Central Government.
  (2) Before giving its sanction under sub-section (1), the Central Government shall, after considering the report given (whether before or after the commencement of this Act) by the commissioner under clause (a) of sub-section (2) of section 27 of the Construction Act and other relevant factors, satisfy itself that the metro railway can be opened without danger to the public using it.
  (3) A sanction given under this section may be either absolute or subject to such conditions as the Central Government thinks necessary for the safety of the public.
  (4) Where any sanction for the opening of the metro railway under this section is given subject to any conditions, such railway shall not be worked or used until such conditions are fulfilled to the satisfaction of the Central Government.