23 C.F.R. § 624.9 – Approval process.

(a) To propose a change in access to the Interstate System, the State DOT shall submit electronically to FHWA a request letter and an IAJR complying with § 624.11 demonstrating that the proposed change in access meets the requirements of this part. Change in access requests will not be accepted from other parties besides a State DOT.
(b) Approval of a change in access to the Interstate System requires a SO&E determination and a final approval.
(c) The SO&E determination shall be based on the safety, operations, and engineering aspects of the request as documented in an IAJR meeting the requirements of this part. The FHWA shall make the SO&E determination, except where FHWA has delegated to a State DOT the authority to make the SO&E determination on behalf of FHWA by entering into a PA that meets the requirements of § 624.13.
(d) If a favorable SO&E determination is made, FHWA will consider whether final approval is appropriate for the proposed change in access to the Interstate System. Final approval may only be granted by FHWA and constitutes a major Federal action under NEPA. Final approval may be granted if the following conditions are met:
1. (1) Applicable transportation planning, conformity, and NEPA procedures have been completed.
2. (2) The alternative covered by the favorable SO&E determination is of the same scope and design as the alternative selected and approved in the NEPA decision.
(e) If the project has not progressed to construction within 5 years of receiving an affirmative SO&E determination, FHWA may require the State DOT to provide verification that the requirements of § 624.7 continue to be met based on current and projected future conditions.