How Does It Happen?
Potholes are perhaps one of the most obnoxious, inconvenient, and potentially harmful forms of asphalt damage there are. Caused in part by poor drainage, water gets trapped beneath the asphalt. During the winter, this water undergoes freezing and thawing. As water expands when it is frozen, this repeated freezing and thawing erodes the asphalt, creating a pocket under the surface that eventually collapses, which forms a pothole.
There are a variety of different ways water can get below the surface of your asphalt to cause potholes, including: insufficient pavement thickness to support traffic during freeze/thaw periods, insufficient drainage, failures at manhole and drain casing, and improperly maintained pavement.