For all purposes of financing, the total cost of any improvement authorized by this article may include every item of expense in connection with the project, and among other items shall also include the cost of constructing or purchasing the superstructure, roadway and substructure of any bridge, the approaches and avenues or rights of way of access thereto and necessary real estate in connection therewith, toll houses and equipment thereof and of the bridge, franchises, easements, rights or damages incident to or consequent upon the complete project, expenses preliminary to construction, including investigation and expenses incident thereto, and prior to purchase or prior to and during construction the proper traffic estimates, interest upon bonds and all such other expenses as after the beginning of operation would be chargeable as cost of operation, maintenance and repairs.
N.J.S. § 27:19-30