Localized pavement surface areas with slightly lower elevations than the surrounding pavement.  Depressions are very noticeable after a rain when they fill with water.

Depression in an access roadway probably caused by subgrade settlement.  Note that the pavement has fatigue cracked significantly as it has settled.

Depression in parking lot probably caused by subgrade settlement.  Again, the pavement has a considerable amount of fatigue cracking where it has settled.


Roughness, depressions filled with substantial water can cause vehicle hydroplaning

Possible Causes

Frost heave or subgrade settlement resulting from inadequate compaction during construction.


By definition, depressions are small localized areas.  A pavement depression should be investigated to determine the root cause of failure (i.e., subgrade settlement or frost heave).  Depressions should be repaired by removing the affected pavement then digging out and replacing the area of poor subgrade.  Patch over the repaired subgrade.