pothole

thumb|300px|Potholes occur with traffic over a roadway that has been weakened by water in the supporting soil structure. A pothole is a pot-shaped depression in a road surface, usually asphalt pavement, where traffic has removed broken pieces of the pavement. It is usually the result of water in the underlying soil structure and traffic passing over the affected area. Water first weakens the underlying soil; traffic then fatigues and breaks the poorly supported asphalt surface in the affected area. Continued traffic action ejects both asphalt and the underlying soil material to create a hole in the pavement.

== Formation == thumb|Factors leading to pothole failure by fatigue in areas subject to freezing and thawing are: 1. Precipitation adds moisture to supporting soil structure. 2. Frost heaving can damage pavement. 3. Thawing can weaken soil structure. 4. Traffic can break the pavement. According to the US Army Corps of Engineers's Cold Regions Research and Engineering Laboratory, pothole formation requires two factors to be present at the same time: water and traffic. Water weakens the soil beneath the pavement while traffic applies the loads that stress the pavement past the breaking point. Potholes form progressively from fatigue of the road surface which can lead to a precursor failure pattern known as crocodile (or alligator) cracking. Eventually, chunks of pavement between the fatigue cracks gradually work loose, and may then be plucked or forced out of the surface by continued wheel loads to create a pothole.