It shall be the duty of the State transportation department or other direct recipient to maintain, or cause to be maintained, any project constructed under the provisions of this chapter or constructed under the provisions of prior Acts.

In any State in which the State transportation department or other direct recipient is without legal authority to maintain a project described in subsection (b), the transportation department or direct recipient shall enter into a formal agreement with the appropriate officials of the county or municipality in which the project is located to provide for the maintenance of the project.

If at any time the Secretary shall find that any project constructed under the provisions of this chapter, or constructed under the provisions of prior Acts, is not being properly maintained, he shall call such fact to the attention of the State transportation department or other direct recipient. If, within ninety days after receipt of such notice, such project has not been put in proper condition of maintenance, the Secretary shall withhold approval of further projects of all types in the State highway district, municipality, county, other political or administrative subdivision of the State, or the entire State in which such project is located, whichever the Secretary deems most appropriate, until such project shall have been put in proper condition of maintenance.

A preventive maintenance activity shall be eligible for Federal assistance under this title if the State demonstrates to the satisfaction of the Secretary that the activity is a cost-effective means of extending the useful life of a Federal-aid highway.