A pothole is a hole in the road surface. It is classed as a pothole when it is deeper than 40mm and at least 300mm wide. 

Potholes usually form during the winter months, often due to snow, ice, and prolonged rain. They happen when water gets into cracks in the road and the surface breaks up and comes away, leaving a hole. 

Potholes are caused by water, weather, and traffic. 

When water gets into small cracks in the road surface, it weakens the layers beneath. During colder weather, that water can freeze and expand, breaking the surface apart. When it thaws, the road is left weaker and more likely to break up under the weight of passing vehicles. 

This process, often called freeze–thaw, is made worse by: 

• Heavy rainfall and storms 

• Winter temperatures 

• High traffic levels, especially on busy roads 

• Older road surfaces that are already worn 

Over time, these factors combine and potholes appear.

Monmouthshire County Council conducts road inspections across the county to identify potential issues. In addition, many potholes are identified through reports from residents, councillors and road users. 

Once a pothole is identified, our officers will assess it using a risk-based assessment. This allows our highways officers to prioritise based on: 

• Risk to road users 

• Size and depth of the pothole 

• Road type and traffic levels 

• Impact on cyclists and pedestrians 

• Location, such as junctions or bends 

The most dangerous potholes are repaired first to keep people safe.

Carrying out repairs 

Depending on risk and conditions, repairs may be: 

• Emergency repairs – Made safe within 24 hours 

• High priority repairs – Repaired aimed within 7-10 days 

• Routine repairs – Repaired aimed within 28 days 

Weather conditions, traffic management and the need for specialist equipment can all affect when a repair is carried out. 

We prioritise defects that pose the greatest risk. Factors include:  

• Safety hazard to road users  

• Volume of traffic  

• Impact on cyclists and pedestrians  

• Weather conditions  

• Whether the defect is deteriorating rapidly  

We understand it can be frustrating when a pothole isn’t fixed straight away. There are several reasons why this can happen. 

Safety comes first – Those that pose the greatest danger to road users are repaired first. Potholes that are smaller or present a lower risk may be scheduled for repair as part of planned works rather than emergency action. Defects that are very minor in nature may not reach our intervention levels and will not be attended to at that time. 

Weather conditions matter – Many repairs require dry conditions to be effective and long‑lasting. During periods of heavy rain, frost, or cold weather, repairs may be delayed to avoid them failing soon after completion. Sometimes, a pothole may receive a temporary repair for safety, even if the weather conditions are not suitable. This will occur knowing that this work will need to be redone. 

Traffic management may be needed – Some roads require traffic lights, lane closures or diversions to allow repairs to be carried out safely. This extra planning can affect how quickly work can take place, especially on busy or narrow roads. 

Temporary vs permanent repairs – At times, a pothole may receive a temporary repair to make it safe, with permanent resurfacing planned for a later date when conditions and resources allow. This approach helps keep roads safe while longer‑term solutions are put in place. 

We recognise that our residents want to see improvements to our roads and for us to respond more quickly to reports of any defects. 

To address these concerns, we are investigating and developing: 

• Longer‑lasting repair materials  

• More proactive inspections  

• Increased machine‑based patching  

• Better public reporting tools