Potholes are holes that form in road surfaces due to traffic stress and weather damage, particularly common in Canadian climates with harsh winters. The freeze-thaw cycle is the primary culprit: water enters small cracks, freezes and expands, breaking apart the pavement. When vehicles drive over weakened areas, the surface collapses into holes. Municipal public works crews repair potholes on city streets using hot or cold asphalt patches. Many cities encourage residents to report potholes through 311 services or online portals. Pothole repair is a significant annual expense for Canadian municipalities, especially after spring thaw.