14 C.F.R. § 151.80

Paving an additional runway on an airport that does not qualify for a second runway under § 151.79 is eligible if the Administrator, upon consideration on a case-to-case basis, is satisfied that—

(a) The volume of traffic justifies an additional paved runway and the layout and orientation of the additional runway will expedite traffic; or

(b) A combination of traffic volume and aircraft noise problems justifies an additional paved runway for that airport.