Road and pavement condition repairs and improvements

Level 1 - Keeping the network safe and serviceable (pot hole repairs)

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. 

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

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

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. With spray injection, each pothole only takes a few minutes. 

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 or add the stretch of road to either our level 2 (patching) or level 3 (resurfacing) programmes.

Where there are more than a few 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 pot hole repair actions and timescales

Our Code of Practice for Highway Safety Inspections (PDF, 2MB) gives full details of how we inspect roads and respond to potholes and other road defects. 

Level 2 - maintaining and protecting the network (patching)

The level 2 programme is a programme of patching maintenance work. Level 2 work protects the overall condition of the road network and stop roads from deteriorating. 

When there are multiple non-urgent defects close together, we will schedule level 2 patching work because patching gives much better value than filling each defect individually. We don't have to go back to the same stretch of road repeatedly to fill separate potholes as they get worse.

If you see a road with a number of defects close together and wonder why we have not treated them, it is likely that we have scheduled the road for level 2 (or level 3) work.

We sometimes patch roads in preparation for level 3 treatments. The patching work should keep the road in a usable condition for a long time, so we add the proposed level 3 project to our rolling programme of work. We then keep the situation under review rather than fixing a specific timeframe for the job.

• Video explaining the criteria in the guidance

Level 3 - investing to improve the network (resurfacing)

Where large scale treatment of a road will deliver better long term value than patching, we include the work in our level 3 programme (known as our Carriageway Improvement Programme). When more than 20% of a stretch of road needs treating, for example, it is more cost-effective to treat the whole stretch of road than to patch.

Level 3 work improves the overall condition of the road. The work involves treatments such as surface dressing, micro asphalt and resurfacing.

Patching

We patch roads and most pavements using asphalt or other materials. 

Patching work can cover both the surface layer of the road and the layers below the surface, depending on what is needed to give the road strength and stability.  

Where a road is scheduled for surface dressing work, we pre-patch in advance to give a smooth and structurally sound surface for the surface dressing treatment. 

We may pre-patch years before before the main work, because patching is often enough to solve immediate issues. We sometimes pre-patch the same area more than once. 

For pavements on older housing estates, we sometimes use micro-asphalt patching. This is a cost- effective and successful treatment for pavements originally laid with thin surfaces that were too thin and have worn away. Newer housing estates don't normally suffer this problem because the standards developers must meet have been improved.

We can do patching work when weather conditions are suitable. The length of time it takes to do patching work depends on the depth we need to work down to and the quantity of material we need to replace. 

Surface dressing

Surface dressing adds a new layer on top of an existing road surface. It is a well-established and cost-effective preventative maintenance treatment. 

We use surface dressing where a road is still structurally sound but the surface is causing issues for road users. The treatment both restores the road surface and adds a waterproof layer that protects the road from water and frost damage. 

Restoring the surface increases skid resistance and improves the appearance of the road. Protecting the road from damage minimises the need for maintenance visits and disruption and keeps roads stronger for longer, reducing the need for expensive resurfacing work (resurfacing can cost up to 10 times as much as surface dressing).

When we programme a road for surface dressing, we patch particular problem areas first to give a suitable base on which to lay the new surface. Patching can take place several years before the surface dressing work.

We use both conventional and micro-asphalt surface dressing, depending on the circumstances.

Conventional surface dressing

For conventional surface dressing, we spray the road surface with bitumen and press in new stone chippings with a roller. On major roads, we apply two layers of both bitumen and chippings. 

Micro-asphalt surface dressing

Micro-asphalt is a mix of bitumen binder and stones suspended in water with cement or hydrated lime. You might also come across the term ‘grip fibre’ - micro-asphalt with fibres added for extra stretch and strength.

Micro-asphalt goes on in 2 layers, each about 5mm. The first layer helps to fill cracks and smooth out dips, and the second gives the surface texture. The mix is blended on site and pumped onto the road.

Because the material is viscous, it does sometimes flow so that it’s a bit thicker against the kerbs than in the middle of the road.

The new surface is very black and can look messy, but it will gradually settle down and look normal again. 

Surface dressing work takes place in the summer, because both types of surface dressing need warm dry weather (though micro-asphalt can tolerate cooler weather than conventional surface dressing). If the weather is not suitable, we might have to change planned dates or stop work and come back later.

Surface dressing normally takes 1 to 2 days. Micro asphalt can be quicker because it is laid cold and strengthens quickly. This means it can be ready for traffic within a few hours, though it continues to cure (harden) for some time after.  

Resurfacing

When more than just the very top layer of a road surface is in poor condition, the road will need resurfacing to make it structurally sound again. 

On most roads, resurfacing involves removing the layers that are in poor condition and replacing them. This is called an inlay. On country roads where there are no kerbs or properties, we may be able to simply add a new surface on top of what’s there – an overlay.

Where we need to remove an existing surface, we bring in a planing machine to chew up the old surface using a rotating drum covered in teeth. 

To lay a new surface, we first clean the road and spray it with bitumen to help the new surface stick. We then use a paving machine to lay a controlled thickness of hot asphalt onto the road.

As part of the work, we sometimes need to dig or plane deeper to fix structural problems. These problems are typically caused by blocked gulleys or by trench digging and reinstatement.

We can do full road resurfacing at any time of year. The length of time it takes to do resurfacing work depends on the depth we need to work down to and the quantity of material we need to replace.

Slurry sealing footways is a preventative maintenance process. It is designed to seal in the surface of a structurally sound footway and extend its life. It fills in minor depressions and voids and provides a more even surface.

Footway slurry seal takes place between March and September.

Patching and repairs may be done where sections of a footway have deteriorated but the whole length does not need replacing. We can do localised footway patching and repairs at any time of year, but schedules can sometimes be disrupted by bad weather.

Footway resurfacing and reconstruction is done when the footway needs a more durable repair. Resurfacing of footway involves removing and replacing the footway surface that is in a poor condition.

Reconstruction of pavements includes replacing block paving with asphalt pavements. These are less of a safety hazard for the public and are easier to maintain. 

We can do footway resurfacing and reconstruction at any time of year, but schedules can sometimes be disrupted by bad weather.

Loose chippings

Surface dressing results in loose chippings because the process needs extra chippings to make sure there is an even spread of stones across the whole area.

We sweep the loose chippings before re-opening the road and after 7 days. We may sweep again if needed. We don't need to close the road again for sweeping. Some loose chippings may still remain after sweeping and other chippings may come loose after we have swept.

There is a 20mph speed limit for the first 24 hours to prevent any accidents caused by chippings.

The loose chippings bed in as traffic passes over. Bedding-in can take some time. Where we surface dress at the end of August, the bedding process lasts through the winter.

Road markings

When we have laid a new road surface, we put temporary signs up to warn drivers that there are no road markings. We normally restore the markings within a week after finishing the work. Junction markings are the first priority.  We do need to close the road to do the work, so we may delay restoring the markings if the road is shortly due to be closed for some other reason and we can do the work at the same time. 

Ironwork

When a new road surface is higher than the previous one, we raise ironwork such as drain and manhole covers to match. We are using a strong asphalt laid around the cover, to give better results. 

We replace or repair any damaged iron work as part of the project.

Closing the road and fixing times for road repair work 

To protect both workers and road users, we close the road when we do surface treatment and resurfacing work. For pothole repair, we can usually keep the road open but may need temporary traffic lights or stop/go signs. Where possible, we only close roads during non-peak times. 

We plan timings for repair work to co-ordinate with other work planned on the road (for example, work by gas, electricity or water companies). This might mean it takes longer for us to do the work - but we only have to close the road once.

To find out more about what what happens when we close a road, see  managing road closures.