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.
(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.