(a) The provisions of this subpart are applicable to the rights-of-way of all Federal-aid highways in which Federal-aid highway funds have participated or will participate in any part of the cost of the highway.

(b) The provisions of this subpart do not preclude acquisition of rights-of-way for use involving mass transit facilities under the provisions of subparts B and D of this part. Rights-of-way made available under this subpart may be used in combination with rights-of-way acquired under subparts B and D of this part.