All you need to know about potholes

How are potholes created?

Water sinks through cracks in the old or weakened road surface which is then soaked up by the road bed under the surface. In the winter months the repeated freezing and thawing of the water helps to break up the road surface especially where it is already weakened.

The traffic moving over this fragile surface pushes the water through the saturated roadbed causing it to weaken and parts of asphalt begin to sink into the eroded parts underneath.

As vehicles continue to pass over the surface it eventually cracks, parts of the asphalt become loosened and a pothole is formed.

How do you repair a pothole?

It depends on the size of the pothole, the type of road and the danger that the pothole poses to road users. Wakefield Council has adopted the national 'Well Managed Highway Infrastructure – Code of Practice' which advocates a risk based approach to highway asset management.

Here are some of the methods that we use to repair potholes:

Temporary repair

For certain locations only a temporary repair is possible to make a pothole safe until a planned permanent repair can be made. In these cases a cold mix of bitumen and chippings is used to fill the hole. This is then smoothed over and compacted.

Cut out and fill

A shape is cut around the pothole using an asphalt saw. The damaged asphalt surface is removed and a hot mix of bitumen and chippings is added to the cut-out area. This is then smoothed over and compacted using a whacker machine.

How quickly is a pothole repaired?

If after a visual risk assessment the pothole meets our emergency criteria, then it will be scheduled in for a repair within 24 hours. If it is not considered an emergency then we will schedule a repair for later on and if we have several defects on one road it is more cost effective to do them all in a single visit. We also need to coordinate these repairs with other planned road works or activities being carried out by the Council or other organisations such as utility companies.

How much does it cost to fill potholes?

There isn't one cost per pothole. They appear on all types of road in different shapes and sizes. Repairing potholes on busy roads for example requires a lot of planning and we may need to close roads or use temporary traffic lights to do the work safely. All this is very costly and we have a limited budget that we want to stretch as far as possible. This is why we have to use a 'risk' based matrix to tackle the defects that are more of a safety issue and to use our resources as effectively as possible.

Isn't it cheaper in the long run to do proper repairs rather than temporary ones?

Sometimes we don't have enough time to plan and complete a permanent repair on a pothole as it may need filling quickly to keep the road safe and to prevent injuries or accidents. The pothole could also be part of an underlying issue with the road surface underneath that requires a more extensive repair.

The weather can have a serious effect on when and how we carry out repairs; we can't use some materials in cold weather for instance. Potholes tend to form mainly during the cold and wet months of the year - the worst conditions to carry out road repairs.

Why can't you just resurface the roads and stop potholes from forming in the first place?

We have over 1,454km of roads across Wakefield District that we are responsible for, in addition to 1,944km of footways and other highway assets such as bridges, street lighting, traffic lights and signage. Potholes are forming all of the time as the road surface deteriorates with usage and with the effects of weather.

Even if we had the funding to resurface everywhere, we would not be able to disrupt the whole network at once and still maintain access for residents, commuters, emergency services, buses and freight.

Wakefield Council has produced a Highways Asset Management Strategy to provide more information on the approach to surfacing site selection.