A pothole (sometimes called kettle and known in parts of the Western United States as a chuckhole) is a type of disruption in the surface of a roadway where a portion of the road material has broken away, leaving a hole. Most potholes are formed due to fatigue of the pavement surface. As fatigue cracks develop they typically interlock in a pattern known as "alligator cracking". The chunks of pavement between fatigue cracks are worked loose and may eventually be picked out of the surface by continued wheel loads, thus forming a pothole. The formation of potholes is exacerbated by cold temperatures, as water expands when it freezes and puts more stress on cracked pavement. Once a pothole forms, it grows through continued removal of broken chunks of pavement. If a pothole fills with water the growth may be accelerated, as the water 'washes away' loose particles of road surface as vehicles pass. In temperate climates, potholes tend to form most often during spring months when the subgrade is weak due to high moisture content. However, potholes are a frequent occurrence anywhere in the world, including in the tropics.
Pothole (or kettle-hole) is also a term for a formation in rivers caused by a whirlpool eroding a hole into rock. The abrasion is mainly caused by the circular motion of small sediments such as small stones in the river. The interiors of potholes tend to be smooth and regular, unlike a plunge pool. An example is the large pothole found in Archbald, Pennsylvania in Archbald Pothole State Park.
The Pothole is a well known sport fishing location in the tailwaters below Powersite Dam in southwest Missouri. It is the uppermost portion of Bull Shoals Lake.
"The holes in our roads" story from the Daily Mail's 7 January 1967 edition reported that there were 4,000 potholes in Blackburn, Lancashire. That story was mentioned in The Beatles's song A Day in the Life.
In 2008 BBC web users voted Sheffield the pothole capital of Britain. An online poll revealed more complaints about the state of the roads there, than anywhere else.