Pothole formation and repair (level one)

Video transcript

Pothole process video transcript

We keep our road safe and serviceable through Make safe repairs to isolated potholes that are located throughout our Network. We identify potholes through a number of sources including reports from customers and we carry out regular inspections of our entire Highway Network. These inspections are carried out by trained and competent inspectors, who will identify pole defects for repair.

The council inspects Highway Network in line with the national code of practice. Defects are assessed using a risk-based approach and our investigatory levels and we will prioritise defects with the most risk to Road users. Reports that meet our investigatory levels are then scheduled for repair in line with approved time scales. We work hard to manage and deal with the increasing number of road defects and our primary aim is to ensure that we maintain a safe and serviceable network.

During periods of adverse weather, roads suffer from heavy rain and freezing conditions; these are both factors that can increase the number of potholes that form in isolated areas. Small cracks develop in the road over time by repeated traffic use, water seeps into the cracks below the surface of the road, which then freezes and expands making the cracks bigger, vehicle movement then causes the cracks to collapse forming a pothole.

The first step of our pothole repair is for our gangs to cut out the pothole and Surround an area with a power saw and a rotating blade. The area which we intend to repair is broken up using a mechanical breaker. The material is then removed from the cut-out areas the surface is then brushed clean to ensure there is no loose materials left in the defective area.

We apply a tack coat to the area that is to be repaired this provides a bond between the existing service and the new tar Macadam that is to be laid. A sealant is applied to all joints to ensure there is a waterproof seal between the new and the existing material. [Music] We then fill the defect with the new material. The new material is then compacted using a vibrating plate until it is flat and flush with the existing Road surface. You can report potholes through fix by Street which can be accessed through the council's website, or in case of an emergency by calling 030012 35020 during working hours or 030012 35025 out of working hours. Reporting via these official channels ensures that your reports have dealt with efficiently and allow us to provide accurate and timely responses on any action taken.

The problem of potholes

Every highway authority is battling with the problem of potholes. We respond to potholes and other localised road defects according to the level of risk to road/pavement users. This means our response time depends on where the defect is, how bad the defect is, and how busy the road or pavement is.

What causes a pothole

Water from rain soaks into cracks in the surface of the road and softens the base layers.

$Traffic breaks up the fractured surface, dislodging small asphalt blocks and forming a pothole. The pothole expands and deepens as traffic and water weaken and flex the surface.$

Freeze-thaw cycles speed up pothole formation. Water freezes and expands, creating cracks and breaking the asphalt around the pothole.

$The soft, fractured road surface, can no longer support the weight of vehicles. The surface begins to break, creating a pothole in the highway.$

Roads naturally deteriorate over time with potholes usually being created by a combination of weather and constant wear from traffic. A long hot summer, followed by a period of prolonged rainfall and then freezing temperatures create the perfect conditions for potholes to develop.

How a pothole forms

Water seeps into the road surface and into the material below (the sub base). Over time if the water cannot adequately drain away it becomes saturated and soft causing the road surface to weaken. Potholes get worse in the winter as the trapped moisture freezes and thaws in a repeated cycle and each time that happens the expanding ice lifts and cracks the surface and the passing traffic will then weaken it further, breaking up the surface until it forms a hollow or pothole. Wear from traffic then expands the pothole.

Potholes also form during the summer months where the foundations of the road have deteriorated and stress from traffic causes potholes in isolated locations.

Urgent safety - critical pothole issues

Where our inspector considers the defect to be putting people at immediate risk, the inspector will make sure the defect is made safe or repaired within a set response time depending on the level of risk.

2 hours for the most urgent issues
2 working days
5 working days
20 working days

Timescales start from the time of inspection.

Filling potholes

The best way to prevent or fix potholes is through planned maintenance, like surface dressing and resurfacing, which stops water from getting in and replaces worn out surfaces. This is cheaper than fixing individual potholes. However, current funding levels aren't enough to proactively maintain roads. Fixing potholes doesn't make the road better but keeps it safe until bigger repairs can be done.

We use a variety of different techniques to fill potholes, depending on the circumstances, including:

Spray Injection

Where appropriate, we use modern spray injection patching techniques to prevent potholes getting worse. This is usually in rural areas where loose chippings are less of an issue. Spray injection machines can fill a pothole in just a few minutes, and the road can be opened again straight after. We can only use spray injection in the spring and summer because it needs warmer temperatures.

Most potholes take between 30 and 45 minutes to fill.

Cut out and patch

We sometimes use a traditional method for fixing potholes, involving cutting out the damaged area, sealing its edges with a special material, and filling it with hot asphalt. This method is adjustable in size and depth and provides a long-lasting solution if the surrounding road is in good condition. If the nearby road structure is deteriorating, the patch may not last long. There's a limit to how large a patch we can make by hand, usually up to 3 square meters, before needing specialised equipment. Hot asphalt can cool down during the day, affecting the quality of the repair, but using hotboxes can help maintain its temperature.

Type A (cold lay material)

Cold material is sometimes used as a fast reactive repair for dangerous potholes that cannot be left until permanent works can be arranged. The speed of the repair helps to ensure safety and accessibility of the network.

Type B (temporary repair)

We sometimes use a temporary repair method which involves sealing its edges with a special material and filling it with hot asphalt. This method will be used when a high volume of defects have been identified. It follows the same process as Type A, however, does not include cutting out of edges.

Pothole repair teams are responsible for clearing up as they go. They take photos of every pothole repair so we can make sure repairs are to a good standard.

After pothole repair work, and for non-urgent issues

Once any urgent repair work is done, or where the defect is not an immediate safety issue, we assess the best long term approach for the location.

We may schedule the defect for future treatment, adding the stretch of road to either our level 2 (patching) or level 3 (resurfacing) programmes.

Where there is a high volume of non-urgent defects on a stretch of road, we will plan patching or resurfacing work rather than individual pothole repairs. This is because it will not be cost-effective to fill each pothole separately.

More details about pothole repair actions and timescales

Our Code of Practice for Highway Safety Inspections (PDF, 1.2MB) gives full details of how we inspect roads and respond to potholes and other road defects.

Pothole data – reports, repairs and spend

The information in the table below shows the number of pothole reports received by Cheshire East Highways along with the number of repairs undertaken by financial year. The table also shows the average pothole repair cost and the total amount spent on pothole repairs which is separated between the council’s revenue budget and the Government Pothole Action Fund.

Pothole table
Year	Number of pothole reports	Number of potholes repaired	Average pothole repair cost
2018/19	1190	No data source	No data source
2019/20	12415	12856	£165.95
2020/21	8909	15637	£92.44
2021/22	8202	27464	£97.03
2022/23	7474	20076	£103.95
2023/24	14116	25602	£111.93

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