N.Y. Transp. Law § 81
The commissioner shall appoint an attorney to represent and appear for the people of the state and the commissioner in all actions and proceedings involving any question under this chapter, or within the jurisdiction of the commissioner under the railroad law, or under or in reference to any act or order of the commissioner, in relation to functions and powers possessed by and all obligations and duties transferred to the commissioner from the public service commission and the department of public service by the provisions of this chapter and, if directed to do so by the commissioner, to intervene, if possible, in any action or proceeding in which any such question is involved. The attorney appointed by the commissioner shall have the duty of commencing and prosecuting all actions and proceedings directed or authorized by the commissioner, and to expedite in every way possible final determination of all such actions and proceedings.
N.Y. Transp. Law § 81