23 CFR 470.109 - System procedures—General.
(a) The State transportation agency, in consultation with responsible local officials, shall have the responsibility for proposing to the Federal Highway Administration all official actions regarding the designation, or revision, of the Federal-aid highway systems.
(b) The routes of the Federal-aid highway systems shall be proposed by coordinated action of the State transportation agencies where the routes involve State-line connections.
(c) The designation of routes on the Federal-aid highway systems shall be in accordance with the planning process required, pursuant to the provisions at 23 U.S.C. 135, and, in urbanized areas, the provisions at 23 U.S.C. 134(a). The State shall cooperate with local and regional officials. In urbanized areas, the local officials shall act through the metropolitan planning organizations designated for such areas under 23 U.S.C. 134.
(d) In areas under Federal jurisdiction, the designation of routes on the Federal-aid highway systems shall be coordinated with the appropriate Federal agency.