The district may not construct or improve a transportation improvement without the approval of the Commonwealth Transportation Board, the county in which the transportation improvement will be located, and, with respect to any improvements located within a participating town, its town council. At the request of the commission, the Commissioner of Highways may exercise the powers of condemnation provided in Chapter 2 (§ 25.1-200 et seq.) of Title 25.1, Article 1 (§ 33.2-1000 et seq.) of Chapter 10, or § 33.2-705, for the purpose of acquiring property for transportation improvements within the district. Upon completion of such construction or improvement, the Commonwealth Transportation Board shall take any affected public highway into the appropriate state highway system for purposes of maintenance and subsequent improvements as necessary. Upon acceptance by the Commonwealth of such highway into a state highway system, all rights, title, and interest in the right-of-way and improvements of any affected highway shall vest in the Commonwealth. Upon completion of construction or improvement of a mass transit system, all rights, title, and interest in the right-of-way and improvements of such mass transit system shall vest in an agency or instrumentality of the Commonwealth designated by the Commonwealth Transportation Board.