The governing bodies of adjacent localities may enter into agreements providing for the construction and operation of highways, bridges, and ferries within their boundaries and for the imposition and collection of tolls for the use of such facilities. Such tolls may be in whatever amount, subject to whatever conditions, and expended for whatever purposes provided for in such agreements. Such agreements shall provide for the design, land acquisition, or construction of primary or secondary highway projects that have been included in the six-year plan pursuant to § 33.2-331, or in the case of a primary highway, an approved project included in the six-year improvement program of the Board. Such agreements shall specify relevant procedures and responsibilities concerning the design, right-of-way acquisition, construction, and contract administration of such projects. Any facility constructed pursuant to the authority granted in this section shall be constructed in accordance with the applicable standards of the Department for such facility. Prior to executing any agreement pursuant to this section, a joint public hearing shall be held concerning the benefits of and need for as well as the location and design of the facility.