(3) For the erection or construction by the board of any pedestrian viaduct, ramp, bridge, tunnel or other pedestrian facility leading to and from a municipal public works which is a motor vehicle parking facility; and any such pedestrian viaduct, ramp, bridge, tunnel or other pedestrian facility shall, for all purposes of this article, be considered to be a part of a municipal public works which is a motor vehicle parking facility with like effect as if the term "municipal public works" were expressly defined in section one of this article to include pedestrian viaducts, ramps, bridges, tunnels or other pedestrian facilities: Provided, That any cost incurred by any municipality or municipalities in erecting or constructing any such pedestrian viaduct, ramp, bridge, tunnel or other pedestrian facility which connects a municipal public works which is a motor vehicle parking facility with a privately owned building or buildings or other privately owned structure or structures shall be paid for by the owner or owners of such building or buildings or such other structure or structures. Any such lease may be privately negotiated without any public notice or advertising, and any such sale may be a public sale pursuant to the provisions of section eighteen, article twelve of this chapter or such sale may be privately negotiated, notwithstanding the provisions of said section eighteen.