The purpose of this section is to implement title 23 U.S.C., section 318 which requires coordination of airport and highway developments to insure (a) that airway-highway clearances are adequate for the safe movement of air and highway traffic, and (b) that the expenditure of public funds for airport and highway improvements is in the public interest.

The requirements of this section apply to all projects on which Federal-aid highway funds are to be expended and to both civil and military airports.

(a) Federal-aid highway funds shall not participate in the costs of reconstruction or relocation of any highway to which this section applies unless the Federal Highway Administration (FHWA) and State officials, in cooperation with the Federal Aviation Administration (FAA) or appropriate military authority, or in the case of privately owned airports, the owner of that airport, determine that the location or extension of the airport in question and the consequent relocation or reconstruction of the highway is in the public interest.

(b) In addition to complying with 23 U.S.C. 318 and insuring the prudent use of public funds, it is the policy of FHWA to provide a high degree of safety in the location, design, construction and operation of highways and airports.

(c) Federal-aid funds shall not participate in projects where substandard clearances are created or will continue to exist.

A finding of public interest by FHWA will be based on compliance with airway-highway clearances which conform to FAA standards for aeronautical safety.