Grants of rights-of-way under Title 23, U.S.C., by the authorized officer of the National Park Service will be made to the appropriate State highway department or to its nominee and based upon considerations of adequate protection and utilization of Federal lands and interests in lands will be subject to (a) all the pertinent regulations of this part except those which the authorized officer, upon formal request of the applicant may modify or dispense with, in whole or in part, upon a finding that it is in the public interest and in conformity with the purposes of Title 23, U.S.C., and (b) any conditions which he deems necessary. Grants of highway right-of-way under this subpart may include an appropriation and release to the State or its nominee of all rights of the United States, as owner of underlying and abutting lands, to cross over or gain access to the highway from its lands crossed by or abutting the right-of-way, subject to such terms and conditions and for such duration as the authorized officer of the National Park Service deems appropriate.