Pavement Inspection

Swelling

A swell is characterized by an upward bulge in the pavement’s surface, a long, gradual wave more than 10 ft (3 m) long. Swelling can be accompanied by surface cracking. This distress usually is caused by frost action in the subgrade or by swelling soil.

Severity Description
Low Swell causes low-severity ride quality. Low-severity swells are not always easy to see but can be detected by driving at the speed limit over the pavement section. An upward motion will occur at the swell if it is present.
Medium Swell causes medium-severity ride quality.
High Swell causes high-severity ride quality.