City of West Sacramento

A pothole is a hole or depression in the roadway that may vary in size and shape. In the City, a pothole is considered an area of missing or deteriorated pavement that is up to approximately 25 square feet in size. Sometimes other pavement surface damage is believed to be a pothole, however, not all road defects are categorized as potholes.

Potholes are caused by a variety of factors such as rain, heat and traffic loading. Typically, traffic loading and natural forces erode the pavement, causing cracks to form. As the pavement continues to experience loading and continues to age, the cracks may grow deeper allowing for water to seep through the pavement. Eventually, the water makes its way into the subbase material which provides support to the pavement and then into the natural soil.  When the temperature drops, the water freezes and expands, and pushes upward into the pavement. As the temperature rises, the base material returns to normal, creating a gap between the pavement and the supporting subbase material. As traffic drives over the weakened area, the pavement surface typically cracks and creates a pothole.

Pothole repairs typically fall into one of these three categories depending on the location, cause of the pothole and the severity:

1.       Pothole Repair: This is the most common method used. This process involves filling the missing area with replacement pavement material. For areas with light traffic, cold patches are typically used because of the quick application process. For high traffic areas or for large potholes, hot mix asphalt is used for higher durability and performance. 

2.       Base Repair: For base repair, road maintenance staff removes the distressed area of pavement where the broken asphalt is allowing for water to get through and is weakening the subgrade material. Once removed, hot mix asphalt is placed, and a roller is used to compact the asphalt.

3.       Rehabilitation: In some cases, the pavement may have multiple potholes and failures. For instances like this, the pavement may require complete rehabilitation. For rehabilitation, the asphalt is completely removed, the subbase material is replaced, and a new layer of hot mix asphalt is applied. This process is very expensive and is completed by Capital Improvement Projects and not road maintenance staff.

Potholes are prioritized based on various criteria, including the size and depth of the pothole, location, speed and amount of traffic on that road. In general, repairs are prioritized in the following order:

1.       Arterial Streets

2.       Collector Streets

3.       Residential Streets

If a pothole is deemed dangerous, it will be treated as an emergency.

Typically, the road maintenance staff responds to pothole repair requests within 48 hours. If the pothole reported has not been fixed within this time period, there are a few possible reasons why:

Weather conditions have created a backlog:

During the winter, rainfall can cause an increase in potholes throughout the City. The increase in potholes may create a backlog causing delays in pothole repairs. It is also possible that the road maintenance staff is assisting with other storm maintenance projects throughout the City and may not be readily available to repair potholes.

The defect reported is not an actual pothole: Some surface defects are often mistaken as potholes but cannot be repaired by the road maintenance staff. If a street has a rough or rutted surface, the case may be that the pavement requires complete rehabilitation far exceeding the available funding or capabilities of the road maintenance staff. 

Utility cuts: Some pothole repairs may be the responsibility of other companies or agencies to fix. Sometimes agencies or private contractors who need access to underground utilities may dig into the roadway during the time of their work. When the work is complete, they are required to repair the street pavement for the section that was removed. If the section of pavement is not properly repaired, the area of the excavation can sink, leaving behind what appears to be a pothole. When this situation arises, the City may require the agency or company to return to correct the pavement, which typically delays the pothole repair.

The pothole was already fixed by the road maintenance staff, but a new pothole formed adjacent to the fixed pothole:

Sometimes the pothole was already repaired, and a new pothole has formed adjacent to it. This usually occurs with older pavements with excessive cracking since the pavement is likely to have base failure in multiple locations.  When this is the case, the pavement may require additional rehabilitation that may exceed the capabilities of the road maintenance staff.

Road Maintenance staff is unable to locate the pothole:

Sometimes the road maintenance staff is unable to locate the pothole due to insufficient information. If this is the case, staff will contact the person who reported the pothole for additional information.  

To extend the life of existing pavement and prevent potholes, the City will apply a sealant to the surface of the street. The sealant that is typically used is called a “slurry seal.” Slurry sealing is the most cost-effective method of preserving and protecting city streets and is done as a Capital Improvement Project and not by City road rehabilitation crews.

Slurry sealing existing pavement in decent condition will seal cracks, preventing water from entering the pavement and making its way down to the supporting material. This can help prevent base failure and will provide cost savings associated with potholes and pavement rehabilitation in the future.