As used in this part, unless the context indicates a different meaning or intent:

(a) “Expressway” means a highway at such locations or between such termini as are herein or may by act of the General Assembly hereafter be established, which is planned, constructed or operated under the provisions of this part and which may provide separation of opposing traffic of vehicles and elimination of cross traffic of vehicles as deemed necessary by the commissioner and access to which is allowed only at highway intersections designated by the commissioner, together with and including all such bridges, buildings, structures and facilities related thereto, including all such restaurant, gasoline station and other service facilities and public conveniences as may be proper purposes for the expenditure of public moneys in connection with such highway, as the commissioner may determine;

(b) “Bond declaration” means a written instrument, signed by the commissioner or Treasurer and filed or to be filed in the office of the Secretary of the State;

(c) “Cost”, when used with reference to construction of an expressway or highway, means, as of any particular date, the costs thereafter to be incurred of planning, designing, constructing and landscaping such expressway or highway and all approaches, bridges and roads connecting thereto or connecting parts thereof, of all lands, property rights, rights-of-way, easements and franchises necessary or convenient for such construction, of all machinery and equipment, and of traffic estimates, administration, engineering, architectural and legal services, plans, specifications, surveys, and estimates of costs and revenues, financing charges, interest prior to or during construction, and all such other expenses thereafter to be incurred as may be necessary or incident to the financing and construction of such expressway or highway and the placing of the same fully in operation, and may include such part as may be determined in a bond declaration related to such expressway or highway of any similar costs and expenses related to such expressway or highway theretofore incurred by the state or the commissioner and such reserves for the payment or security of principal of or interest on bonds as may be determined in a bond declaration related to such expressway or highway;

(d) “Treasurer” means the State Treasurer and includes each and all of his successors in office or authority; and

(e) “Highway”, as used in sections 13a-22 and 13a-25, means any highway laid out or maintained by the state.