Pothole FAQs
What is a pothole?
Potholes are a type of isolated failure in an asphalt pavement where material is missing, and the presence of traffic passing over the weakened areas causes the pavement to break apart and the size of the hole to increase.
When does it look like a pothole, but it's not a pothole?
Roadway damage or issues that can act like a pothole when you’re driving, but are not actually potholes, include faulting, when there is a difference in the elevation across a joint of the roadway, or pavement failure, which is cracked, broken, depressed or sunken pavement.
How do potholes form?
Water weakens the supporting soil structure and then traffic breaks the poorly supported asphalt surface.
- Potholes are formed by water, traffic, excessive heat, freezing and freeze-thaw cycles, wear and tear, and time.
- Areas where the drainage is poor are more prone to potholes.
- Areas where there is heavy traffic are more prone to potholes.
How are potholes fixed?
City crews use hot asphalt to repair pot holes. In a rain events, emergencies / after hours or when the weather is too cold for hot asphalt we will use cold patch as a temporary repair. Utility companies like PG&E, ATT, VS&F and the Water department among others will place temporary cold patch down over their repairs until they can get a contractor out to make the permanent repair with hot asphalt.
The pothole I reported was filled, but now it has appeared again. Why didn't the repair fix it?
Many pothole patches perform well over several months, or even years. If there are underlying roadway problems, patching the pothole will only be a temporary repair. Weather conditions while the repair was made, the amount of traffic above the pothole, and ground settlement can all impact patch performance. If the underlying cause of the pothole is not corrected, the pothole patches may fail or new potholes may form. See below under Road Repair Information for more details.
Can potholes be fixed in the winter months?
Yes, the cold-patch asphalt repair material that the City uses can be used in wet conditions. Cold patch asphalt can be applied right from the container without heating. The material contains pressure sensitive polymers that speed up the setup of the material. Conditions that make it difficult to repair potholes in the winter months include temperatures below 40 degrees as cold material is hard to work with, also recent rain can make it difficult to see potholes.
What if I am reporting something that is "not a pothole"?
There are many types of pavement defects that can be difficult to distinguish from potholes. Weather the issue reported is a pothole or not , SeeClickFix will automatically create a service request for our staff to assess.
What other issues can cause problems with the roadway besides potholes?
Other pavement issues that are not potholes (and often involve a much more complex repair process) include:
Pavement cracking:
- alligator cracking (associated with a structural failure)• block cracking (looks like large, interconnected rectangles)
- linear cracking (cracks that are parallel to the pavements centerline or laydown direction)
- transverse cracking (single cracks perpendicular to the pavement's centerline or laydown direction)
- edge cracks (travel along the inside edge of a pavement surface within one or two feet)
- joint reflection cracks (cracks in a flexible pavement overlay of a rigid pavement that occur directly over the underlying rigid pavement joints)
- slippage cracks (crescent-shaped cracks or tears in the surface layer of the asphalt)
Depressions: localized pavement surface areas with slightly lower elevations then the surrounding pavement.
Rutting: channelized depression in the wheel-tracks. Results from lateral movement of any of the pavement layers
Shoving: formation of ripples across a pavement
Upheaval: localized upward movement in a pavement due to swelling of the subgrade
Raveling: on-going separation of aggregate particles in a pavement from the surface downward or from the edges inward
Road Repair Information
Investments must be made into street infrastructure to create long-term solutions to potholes and other pavement issues. There are three pavement treatment types:
Pavement Preservation is proactive maintenance of roads to prevent them from getting to a condition where major rehabilitation or reconstruction is necessary.
Pavement preservation includes:
- Fog seals - specially formulated asphalt emulsion (thin liquid oil) to an existing asphalt pavement surface. Typically applied on an intermittent or cyclical basis. Commonly used on roadways with minor cracking, faded color, or where a fog seal would help extend pavement life.
- Slurry seals - an application of a mixture of water, asphalt emulsion, aggregate and additive to an existing pavement surface. Similar to a fog seal but has aggregates as part of the mixture.
- Microsurfacing - similar to a slurry seal. Typically applied on an intermittent, project-specific basis.
- Chip seal - two step process that includes an application of asphalt emulsion and then a layer of crushed rock to an existing asphalt pavement surface. Commonly used on roadways with moderate cracking.
Pavement Rehabilitation is carried out on pavements that exhibit distresses beyond the effectiveness of maintenance but do not yet warrant complete reconstruction. Pavement rehabilitation includes:
- Rubberized asphalt - hot-mixed asphalt pavement containing crumb rubber. Frequently used as the surface course material when roads are resurfaced or reconstructed.
- Asphalt overlay - applies a new layer of asphalt over the current one. Any potholes or asphalt issues are repaired prior to the installation of the new layer.
Pavement Reconstruction is completed when a roadway has deteriorated to a point where rehabilitation becomes too expensive and can no longer perform well due to the condition of the underlying pavement. Pavement reconstruction includes:
- Full-depth reclamation - a recycling method for reconstruction of existing flexible pavements where the old pavement is ground up and used as a foundation for the new roadway.