No bridge or tunnel other than those specified in § 33.2-1700 for the use of the traveling public shall be constructed and operated by the Commonwealth or by any county, municipal corporation, or political subdivision of the Commonwealth, or by any agency or instrumentality, partnership, association, or corporation, within 10 miles of any terminus of any project acquired or constructed under the provisions of this chapter, and no franchise shall be granted for the operation of a ferry within 10 miles of any projects for the acquisition or construction of which revenue bonds have been authorized under this chapter, except under a written permit granted by the Board, which is hereby exclusively authorized to grant such permits under the terms and conditions of this chapter. No such permit shall be granted by the Board until it ascertains by an investigation, including a hearing upon such notice and under such rules as the Board may prescribe, that there is an urgent public need for the operation of such bridge, tunnel, or ferry and that its operation will not affect the revenues of any such project of the Commonwealth so as to impair the security of any revenue bonds issued for the acquisition or construction of such project. The distance of 10 miles specified in this section shall be measured in a straight line between the nearest points of such projects. However, nothing in this chapter shall apply to an existing ferry route, temporarily discontinued, if the ferry was established prior to 1940.