About Potholes and How They Are Repaired

Overview

Potholes are a major inconvenience on City roads. They can occur year round, but mostly form in the early spring when the weather freezes and thaws repeatedly.

You can report a pothole online, or read below to learn how and why potholes form and how they are repaired.

Causes of Potholes

When it rains, water seeps from the road surface into the road base through cracks in the road. In winter, this water freezes and expands, forcing the road surface upward. When the water thaws and evaporates, a hole is created underneath the road surface. Then, when a car drives over this area, the weight of the car collapses the road surface into the hole. Additional traffic makes the pothole bigger until it can be fixed.

In late winter and spring in St. Louis, changes in weather patterns cause the roads to freeze and thaw repeatedly, creating the conditions for potholes to form.

What the City Does About Potholes

The Street Division patches potholes year round with either a cold asphalt or a hot asphalt. The cold asphalt works better in cool/wet temperatures and the hot works better in the warmer months.

The most difficult potholes are areas the Street Division calls alligator cracked, where the pavement has multiple cracks that look like alligator skin. Patching one part of an alligator cracked area does not prevent other areas from crumbling, so it may need to be patched multiple times before the whole area can be replaced.

Planning and Scheduling Pothole Repairs

Usually potholes are scheduled to be patched in order of street type: 

1. Major arterials (like Kingshighway Blvd or Florissant Ave) 
2. Secondary arterials (like St Louis Ave or Compton Ave)
3. Residential streets
4. Alleys

If there are a large amount of potholes to fix, the Street Division will work on them ward by ward, which is much more efficient and allows more potholes to be fixed in a given time period. View reported and repaired potholes on the pothole map.