Corrugation

Corrugation is a series of closely spaced ridges and valleys (ripples) occurring at fairly regular intervals (usually less that 5 ft [1.5 m]) along the pavement. The ridges are perpendicular to the traffic direction. Traffic action combined with an unstable pavement surface or base usually causes this type of distress.

Severity	Distress Example	Description
Low	No Photo	Corrugations are minor and do not significantly affect ride quality. Runways and High-Speed Taxiways: < 1/4 in (6 mm) Taxiways and Aprons: < 1/2 in (13 mm)
Medium	No Photo	Corrugations are noticeable and significantly affect ride quality. Runways and High-Speed Taxiways: 1/4 to 1/2 in (6 to 13 mm) Taxiways and Aprons: 1/2 to 1 in (13 to 25 mm)
High		Corrugations are easily noticed and severely affect ride quality. Runways and High-Speed Taxiways: > 1/2 in (13 mm) Taxiways and Aprons: > 1 in (25 mm)