(a) Proposals for system actions on the National Highway System shall include a route description, a statement of justification, and statements of coordination with adjoining States on State-line connections, with responsible local officials, and with officials of areas under Federal jurisdiction.

(b) Proposed modifications to the National Highway System shall enhance the national transportation characteristics of the National Highway System and shall follow the criteria listed in § 470.107. Proposals shall also consider the criteria contained in appendix D of this subpart.