Another commentor explained how potholes form, but I'll add that Cleveland doesn't have a lot of money and tends to defer maintenance.
When I was living there, road signs saying "Steel Plate on Road" were a common sight. I remember the city fixed a water pipe and instead of re-paving the street, they just left several giant 4ft x 8ft steel plates with corresponding sign for over a year.
When I was living there, road signs saying "Steel Plate on Road" were a common sight. I remember the city fixed a water pipe and instead of re-paving the street, they just left several giant 4ft x 8ft steel plates with corresponding sign for over a year.