1. Purpose and scope of the guide
Highways are fundamental to the functioning of communities, providing critical connections for residents, businesses, and public services. Well maintained roads support economic growth – helping businesses and workers operate efficiently, facilitating trade and commerce. Roads also deliver social value for communities, allowing people to visit family and friends, and as an important part of the public realm.
Accounting for 98 per cent of the total network in England, local roads are of particular importance to residents. Local roads are what people see when they leave their house, and almost all journeys start and end on local routes, and they serve a wide range of users – from pedestrians to cyclists, cars, buses, lorries, wheelchairs and electric scooters.
Because of their importance, the condition of the highways receives significant scrutiny from residents. Road conditions are highly visible to residents, and potholes or poorly executed repairs can generate high volumes of complaints. The LGA’s October 2024 polling on resident satisfaction found that road maintenance has the highest level of dissatisfaction of all services, with 59 per cent of respondents dissatisfied. In March 2025, the Independent Commission on Neighbourhoods found that “potholes in the road” was ranked by residents as the biggest challenge facing their neighbourhood.
The sector is making the case to Government for more funding, but councils also need to maximise the value of every pound.
The Local Government Association, councils, industry groups, the public, Members of Parliament, and many others are making the case to Government that increased and long-term funding for highways maintenance should be a priority in the upcoming Spending Review.
However, given the significant backlog in highways maintenance and wider pressures facing councils, it’s likely that funding will always be a constraint for the sector. That means it is particularly important for councils to be exploring all opportunities to maximise the value of their spending on highways maintenance.
Best practice maintenance treatments and emerging technology can help councils in this mission.
Highways maintenance takes many forms, with a variety of types of treatment available depending on when and how a council chooses to intervene. Each of these treatments has different strengths and is designed for different circumstances. To make best value of their resources, councils need to be prioritising the right activity, in the right place, at the right time.
Innovations in technology present an opportunity to support councils to take on this challenge. The latest scanning technology provides better, faster data on the condition of their road network. Artificial Intelligence (AI) can analyse these images, flagging dangerous potholes and identifying small defects before they turn into major problems. Work management systems help councils analyse data from across their authority, supporting officers to plan which investments should be prioritised to squeeze as much value from the limited resources at their disposal.
This guide is timely as DfT is changing the standards regarding road condition data which councils are asked to collect and report to Government. This means many councils will need to update their road monitoring systems over 2025 and 2026.
This guide is aimed at councillors. Cabinet or committee members with responsibility for highways may find it most valuable, but we hope it will be useful to all councillors, particularly given the level of resident interest in highways maintenance matters.
This guide aims to increase awareness for elected members of best and emerging practices related to preventative maintenance, reactive maintenance, and the use of technology and AI in highways maintenance. It also seeks to explain the opportunity of these practices and some of the key factors that councillors and councils should consider as part of decision making in this area. We also suggest some areas you may want to explore in conversations with officers.
The principles and practices outlined in this guide aim to be broadly applicable, but every council has a unique set of local factors.
We have supplemented this advice with real-life case studies of how councils across England have implemented these approaches. The guide also sets out links to wider resources which provide additional detail on the issues discussed in this guide, and signposts some of the other organisations across the sector who aim to support councils to deliver good outcomes for residents.
This guide was prepared for the LGA by Rebel Group. We are grateful to many across the sector who supported the production of this guide.
In chapter 2 we set out the context on councils’ duties regarding highway maintenance, the challenges they face in maintaining and delivering these, and the role of councillors.
In chapters 3 and 4, we set out a number of best practice techniques to deliver preventative and reactive maintenance and key factors that councils will want to consider in deciding how to undertake maintenance.
In chapter 5 we describe the opportunities available to councils from adopting innovative technologies and how these can support them to maximise the value of their investment in the highway network.
2. Context
The legal duty to maintain safe highways
Under the Highways Act 1980, councils have a statutory duty to maintain their roads in a safe and serviceable condition. Failure to meet these obligations can lead to legal risk and compensation claims, as councils face liabilities if poor road conditions cause damage or injury and they were negligent in their duties to repair an issue they knew about or should have known about.
Compensation claims are on the rise, with FOI requests from the RAC to the 21 largest highway authorities in England finding that the number of claims more than doubled between 2022 and 2023.
Councils have a difficult task to balance competing priorities in the face of significant constraints and headwinds
Managing a network of 183,000 miles is already a challenging job for the 153 local highway authorities in England, but councils face a significant number of headwinds and constraints which make this more complex:
- Funding constraints – limited and often short-term funding allocations hinder strategic, long-term investment in road maintenance. High inflation over recent years has meant that many authorities have faced a real terms cut in the size of their maintenance budgets.
- Backlog of repairs – years of underinvestment have created a significant backlog, requiring reactive treatments that are more expensive and less effective. In 2019, DfT estimated there was a £7.6 - £11.7 billion backlog of maintenance work. But the Asphalt Industry Alliance’s 2025 ALARM survey estimated this had risen to £16.8 billion.
- Aging infrastructure – historic road-building practices and materials may not be suited to modern traffic volumes and climate conditions. Life-expired bridges and old concrete block roads are two common examples of this.
- Increasing traffic loads – heavier and more frequent traffic, including HGVs, accelerates road wear and deterioration.
- Changing requirements – many councils are increasingly keen to support active travel modes such as cycling. These use different areas of the highway surface (e.g. closer to the kerb than cars) and users may be more at-risk to injury from potholes than car drivers. This could require councils to prioritise pothole repairs that would previously have been seen as low priority.
- Streetworks and utility excavations – increasing demand by utility companies has led to more streetworks which can degrade road surfaces and disrupt planned maintenance. [The LGA has also recently published a guide on how councils can manage the disruption caused by streetworks]
- Workforce capacity – many local highway authorities and construction companies report issues with an aging workforce and a limited supply of new skilled workers. This creates competition between authorities and risks losing expertise as the sector’s workers approach retirement. This also leads to risks around the sector’s ability to absorb the latest innovative technologies and techniques.
- Climate change – a long-term increase in rainfall and extreme weather conditions will accelerate deterioration of the road network. This creates new demands on funding, with infrastructure needing to be more resilient to changing weather patterns.
- Imperfect information on highway assets – councils don’t always have full information on the exact condition of their highway network today, and it is difficult to predict where the highest risk issues are likely to emerge in the future. Many highway authorities manage vast networks with a diverse mix of roads from A roads through to unclassified country lanes.
Budgets will never stretch far enough to fund all the activities that councils would like to deliver, which means they must make strategic decisions about where, when, and how to invest in maintenance.
DfT has introduced a new incentive mechanism
On 23 March 2025, The Transport Secretary announced a £500m uplift for local highway maintenance budgets in England. This was accompanied by details of an incentive mechanism, with 25 per cent of this funding withheld unless councils publish details on their websites of annual spending on highway maintenance; the number of potholes filled each year; future resurfacing plans; road condition; and how they are minimising disruption from streetworks. Councils will also be required to show how they are spending more on preventative maintenance, what they are doing to delivery innovation and efficiency, and that they have plans in place for wet winters.
Councillors have an important role
Councillors make a number of key decisions that impact how their authority delivers its highway maintenance. These vary from authority to authority, but could include:
- Signing off highway asset management strategies and policies.
- Setting the overall highways maintenance budget.
- Deciding funding allocations between highways maintenance programmes and schemes.
- Influencing which problems are prioritised for remediation.
- Providing constructive challenge to officers on the way their council delivers highway maintenance and supporting reform where needed.
- Answering resident queries on the council’s plans for future highway maintenance.
- Providing feedback from residents to officers on the quality of previous highway maintenance work.
3. Preventative maintenance
The importance of preventative maintenance
Preventative highway maintenance involves routine inspections, minor repairs, and surface treatments designed to slow road deterioration and extend pavement life.
An asphalt road will naturally degrade through a process of oxidisation, through exposure to the elements, UV light, pollutants and trafficking. This will cause the road to become brittle and crack, which leads to water ingress, and eventually potholes to form.
To protect the asphalt, it is important to ensure that water is removed from the surface, through maintenance of highway drainage systems. It equally important to ensure that the road surface is sealed, to prevent water ingress which gets into the fabric of the road, causing extensive damage.
Throughout the road’s lifecycle there are opportunities to apply a low cost, preventative surface treatment, that will keep roads in good condition, arrest decline, and prevent future formation of potholes.
This approach might include sealing cracks and joints, applying protective coatings, and addressing drainage issues to prevent more severe damage.
Investing in preventative maintenance is important for several key reasons. Primarily because it offers better value for money than replacing on fail, improves the condition and lifespan of road assets, prevents potholes and reduces disruption for residents.
The key principle is that by intervening early and treating defects when they are smaller and less complex, councils can avoid expensive and damaging problems emerging.
A desire to address the existing backlog of problems can lead councils to adopt a “worst first” replace on fail approach, fixing potholes rather than proactively maintaining the rest of the network. This is understandable, given pressure from residents to fix potholes.
However, by de-prioritising preventative maintenance, councils risk entering a downward spiral where the existing road network deteriorates at a faster rate than existing problems can be fixed, and the overall condition of the network reduces. It is impossible to improve the overall condition of the local highway network without an appropriate plan of preventative maintenance.
Preventative maintenance provides good value for money
There is a perennial tension between preventing future problems and addressing the problems that are affecting residents today. That’s why it’s important to develop an approach that balances early life preventative treatment, with permanent repair solutions, and end of replacement.
Preventative maintenance delivers better long-term value for money than reactive maintenance – avoiding problems all together and is cheaper than fixing them. A number of studies have attempted to quantify the extent to which preventative maintenance can deliver savings for councils, including:
- The DfT’s Potholes Review reported that planned preventative maintenance is at least 20 times less expensive than reactive maintenance.
- The Road Surface Treatments Association estimates that surface treatments range from £3.50 - £8 per square metre, but reactive pothole repairs can cost over £80 per repair. The Asphalt Industry Alliance’s 2025 ALARM survey estimated that the average cost of filling a pothole across England and Wales was £81.62-106.52
- Evidence submitted to the Public Accounts Committee’s 2025 report on local road maintenance reported that planned works were 35% cheaper than reactive fixes.
The exact savings available depend on local factors, but when delivered at the right time and in the right way, preventative maintenance can deliver significant savings for councils.
Condition and lifespan of assets
Preventative maintenance helps to prolong the service life of highway assets and improve their overall condition. Keeping water out of the road surface is a key strategy in prolonging its life. Regular preventative treatments, can seal the early symptoms of damage, prevent water ingress, and help stop potholes from appearing in the first place.
By maintaining roads in a steady state of condition, it's even possible to achieve net carbon savings. A preventative approach aims to manage and maintain road conditions far more effectively and extend road lifespans, potentially indefinitely.
Disruption for residents
Proactive maintenance reduces the likelihood of major asset failures that can cause substantial disruption and require extensive and prolonged repair works. Effective maintenance also contributes to reducing damage to roads during adverse weather events, thus minimising network disruptions that can have significant economic costs.
Preventative maintenance can often be planned so that it is delivered at a time that minimises disruption. This isn’t always possible when a problem requires an urgent fix, for instance a deep pothole on a key route.
Factors to consider when choosing a repair method
There are a number of preventative treatments available to highway authorities. Each of these is best-suited to different circumstances, with a number of factors to consider when choosing the most appropriate course of action. These include:
- Condition of the highway – each treatment is designed for a different stage of the lifecycle of a road.
Traffic level – some treatments are naturally less durable and so are more suited for lower-traffic areas. - Location of the road – the delivery of some treatments can leave dust or stone chippings, which may be undesirable in highly urbanised areas. On the other end of the scale, heavy-duty machinery may find it challenging to navigate challenging or remote geographies.
- Disruption – some treatments can be delivered quickly and have the road reopened for traffic within an hour. Other treatments require the road to be closed for one to two days, and/or temporary traffic limits for multiple days afterwards. These impacts are relatively short in the lifespan of a road, but disruption could be a critical factor if a road serves key community services (e.g. hospitals) or diversions are impractical.
Preventative treatments
In this section, we summarise six key preventative treatments, their benefits, the circumstances in which they are most effective, and wider factors that councils might wish to consider when deciding whether and how to invest in road maintenance. We cover:
- Preservation (penetrative and non-penetrative)
- Rejuvenation
- Crack and joint sealing
- Surface dressing
- Microsurfacing (microasphalt)
- Retexturing
Cost estimates for each treatment are included. These are based on industry standard rates across the country but are purely indicative and you will want to engage officers and local suppliers to get a better estimate. A number of factors influence the true cost rate, including the level of upfront capital investment required, regional variations, and the quantity of work your council delivers, among others. Preventative treatments have a strong track record in the UK with documented case studies both within local highway authorities and national road operators over 20 years.
| Preservation | ||
|---|---|---|
| Description |
Spray applied surface treatment. Can be non-penetrative bituminous emulsion treatment which is not used on high speed roads – typically urban unclassified roads during the day only Penetrative treatments are solvent based and can be applied night or day. Can be reapplied, typically every five years. Penetrative preservation seals micro cracks in the top 10mm, and supports aggregate retention. Both preservation treatments seal the road surface to prevent water ingress, and protect against exposure to the elements, UV light and trafficking.
|
|
| Benefits | Keeps good condition roads in good condition for up to five years, when it can be reapplied. Treating at year five intervals will save multiples of £81.62 per pothole repair from typically years 8-10. Combined with eventual renewal of the surface course at years 10-15 at £25-30 per m2 this offers a 50% cost and carbon saving over a sixty year whole lifecycle | |
| Cost | £3-4 per m2 | |
| Where appropriate | Mid life treatment for roads still in good condition, or roads with very minor cracks (which should be treated before or after application) | |
| Which roads are suited for this treatment? | ||
| Highway condition | Roads still in good condition in year five but could extend to year 7, when the onset of deterioration is initiated. | |
| Traffic level |
Non penetrative – Low trafficked roads Penetrative - All traffic levels |
|
| Size of repair | Full-width of carriageway and best value over larger distances | |
| Key features of the treatment | ||
| Delivery time | Can treat up to 40,000m2 in a single shift. Roads reopen withinn 30 minutes to two hours depending on temperatures. | |
| Carbon |
Low carbon solution both in the short term, and medium to long term. Non penetrative preservation - 0.28 kgCO2e/m² Penetrative - 0.33 kgCO2e/m² |
|
| Weather | Needs dry weather during application. | |
| Rejuvenation | |
|---|---|
| Description | Emulsion-based surface treatment sprayed onto the road. It penetrates and rejuvenates the bitumen through the full depth of the surface course, through a chemical process effectively glueing it back together the surface is restored to its original specification. |
| Benefits | Keeps good condition roads in good condition for up to five years, when it can be reapplied. Treating at year five intervals will save multiples of £81.62 per pothole repair from typically years 8-10. Combined with eventual renewal of the surface course at years 10-15 at £25-30 per m2 this offers a 50% cost and carbon saving over a sixty year whole lifecycle |
| Cost | £2.50-3.50 per m2 |
| Where appropriate | Mid-life treatment for all types of road (urban/rural) and traffic-level that are structurally sound but have early signs of defect. |
| Which roads are suited for this treatment? | |
| Highway condition | Roads still in good condition in year five but could extend to year 7, when the onset of deterioration is initiated. |
| Traffic level | All traffic levels. |
| Size of repair | Full-width of carriageway and best value over larger distances |
| Key features of the treatment | |
| Delivery time | Can treat up to 70,000m2 in a single shift. Road can reopen within 30 minutes to two hours depending on temperatures. |
| Carbon |
Low carbon solution both in the short term, and medium to long term. 0.03 kgCO2e/m² |
| Weather | Needs dry weather during application. |
| Crack / joint sealing | |
|---|---|
| Description | Debris is cleared out of cracks in the road. Then a specialised adhesive sealant is applied. This helps to prevent the infiltration of moisture and incompressible materials into the pavement that may cause damage if left untreated. |
| Benefits | Fast to apply and more cost-effective than repairing potholes. Seals early signs of defect to prevent water getting in and causing more damage. |
| Cost | Low but highly variable (see note) |
| Where appropriate | Roads that are showing early signs of wear-and-tear in the form of cracking, or in the surface joint (usually in the centre of the road). |
| Which roads are suited for this treatment? | |
| Highway condition | Applied to surfaces at a relatively early stage of the highway lifecycle when defects first begin to emerge. |
| Traffic level | All traffic levels. |
| Size of repair | Very targeted application is needed as this is only suited to small areas and cracks. Larger cracks may require reactive patching treatments or preventative treatment across the full road surface (e.g. surface dressing or micro asphalt). |
| Key features of the treatment | |
| Delivery time | Fast and road can reopen almost immediately. |
| Carbon | Low – 4.5kgCO2e/m² |
| Weather | Typically done in spring or autumn to avoid seasonal variation in cracks (e.g. expansion in winter). |
| Surface dressing | £4-5 per m2 |
|---|---|
| Description |
Involves spraying a sticky bitumen binder on the existing road surface, before a single or double layer of chippings is applied and rolled in. Requires the road to reopen at low speeds to bed in the chippings before a final sweep. Recent developments include encapsulation which locks down the chippings and has the aesthetics of a conventional surface (i.e. black).
|
| Benefits |
Can restore a road back to good condition, extending its life expectancy by up to 10-15 years (depending on traffic volumes). Much cheaper than replacing asphalt. Treating mid-life roads at £4-5 per m2 will prevent them falling into poor condition, where expensive and unpredictable repairs (multiples of £81.62) will be required, and will require replacement £25-30 per m2.
|
| Cost | £4-5 per m2 |
| Where appropriate |
Mid-life condition roads where minor, localised defects may exist, which must be repaired prior to application. Can be applied to all types of road environment (urban/rural) and traffic volumes (heavy or light).
|
| Which roads are suited for this treatment? | |
| Highway condition | Roads in good to fair condition (typically years 7-10). Any localised defects will require repair ahead of treatment. Surface dressing will follow the existing profile and will not repair any minor defect so a good road profile is needed to start with. |
| Traffic level | All traffic levels |
| Size of repair | Full width of carriageway and best value over larger distances |
| Key features of the treatment | |
| Delivery time | Can treat up to 40,000m2 in a single shift. Roads can be reopened very soon after application but 20 mph speed limits must remain in place until final sweep is completed. |
| Carbon |
Low carbon solution both in the short term, and medium to long term. Single dressing - 0.8 kgCO2e/m² Double dressing (racked in) – 1kgCO2e/m² |
| Weather | Needs dry weather during application. |
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| Microsurfacing (Microasphalt) | |
|---|---|
| Description |
Microsurfacing treatment is a cold mixture of bitumen emulsion, aggregate, fibres and cement, mixed on site in the vehicle, laid in a single or double layer at a depth up to 15mm, on the existing road surface. This regulates out minor road defects, and provides a regular, sealed road surface.
|
| Benefits |
Restores roads back to good condition, extending its life expectancy by up to 10-15 years (depending on traffic volumes). Much cheaper than replacing asphalt. It is very quickly applied and roads can be quickly reopened within 30-60 minutes. Treating mid-life roads at £6-8 per m2 will prevent them going into poor condition a short time later, where expensive and unpredictable repairs (multiples of £81.62) will occur and the road will require replacement for £25-30 per m2.
|
| Cost | £6-8 per m2 |
| Where appropriate |
Standard microsurfacing is best suited to less busy roads, with fewer than 250 commercial vehicles per lane per day. Cold applied ultra thin surfacing (CAUTS) can be used to treat busier roads with more than 250 commercial vehicles per lane per day. |
| Which roads are suited for this treatment? | |
| Highway condition | Roads in good to fair condition with good structural condition. Microsurfacing will regulate out minor surface defects |
| Traffic level | All traffic levels. |
| Size of repair | Full width of carriageway and best value over larger distances. |
| Key features of the treatment | |
| Delivery time | Roads can be reopened 30 minutes after application. |
| Carbon | 1.8 kgCO2e/m² |
| Weather | Needs dry weather during application. |
| Retexturing | |
|---|---|
| Description |
Polished roads with poor texture and low skid resistance can be retextured using various methods: hydro (water under pressure), shot blasting or fine milling to retexture concrete. Water blasting can be used to remove any debris (dust, oil etc.) or on ‘bleeding’ (smooth and shiny) roads to strip excess asphalt binder to expose the chippings. Captive shot blasting is used to re-abrase the aggregate and remove any debris.
|
| Benefits | Improves texture and skid resistance, to reduce risk of collisions |
| Cost | £3.50-4.50 per m2 |
| Where appropriate | Roads that have poor texture and skid resistance, but are otherwise in good, structural condition. |
| Which roads are suited for this treatment? | |
| Highway condition | Roads in good to fair condition. Low texture or SCRIM (skid resistance) |
| Traffic level | All traffic levels |
| Size of repair | Full width of carriageway, wheel tracks, or localised areas |
| Key features of the treatment | |
| Delivery time | Very quick. Roads can be reopened very soon after completion of works. |
| Carbon |
Hydroblasting - 0.3 kgCO2e/m² Shot blasting- 0.4 kgCO2e/m² |
| Weather | Needs dry weather during treatment. |
End of life replacement
Untreated roads at the end of their life will require unpredictable and expensive repairs before becoming unserviceable and therefore require replacement. Options for replacement include to reduce reduce cost, carbon or disruption include:
- Resurfacing
- Geosynthetics and steel meshes
- In-situ recycling
- Ex-situ recycling
| Full resurfacing | |
|---|---|
| Description | Layers of worn-out, failing road can be removed using a road planer. This could typically be surface course (30-50mm), binder and surface course (100mm), or deeper into the base, binder and surface course, typically up 300mm. It’s then replaced with a new layer/s of asphalt, which are then compacted to create a durable and even surface. |
| Benefits |
Restores a life-expired road to good condition, improving grip, smoothness, longevity and structural integrity. Avoids ongoing reactive maintenance to fix recurring potholes. |
| Cost | £25-50 per m2 |
| Where appropriate | Life-expired roads, suitable for all traffic levels. |
| Which roads are suited for this treatment? | |
| Highway condition | Surfaces at the end of their life with substantial damage and requiring frequent reactive repairs. |
| Traffic level | Suitable for all traffic levels. |
| Size of repair | Full width of carriageway and best value over larger distances. |
| Key features of the treatment | |
| Delivery time | Can require up to one day for the new surface to cure. |
| Carbon |
Higher than other preventative treatments due to the need to replace and transport large quantity of material. 40mm surface course replacement - 7.2 kgCO2e per m2 100mm binder and surface replacement - 17.4 kgCO2e per m2 |
| Weather | Typically done in warmer months suitable for asphalt application. |
| Geosynthetic and steel meshes | |
|---|---|
| Description |
Meshes that can be introduced between layers of asphalt preventing reflective cracking through the layer above.
|
| Benefits |
The depth of asphalt replacement can be reduced, saving costs and carbon. It provides future resilience of underlying material failure, impacting on the asphalt layer above it. |
| Cost | £5-6 per m2 |
| Where appropriate | Used on life-expired roads, where asphalt replacement is required. |
| Which roads are suited for this treatment? | |
| Highway condition | Surfaces at the end of their life with substantial damage and requiring frequent reactive repairs. |
| Traffic level | Suitable for all traffic levels. |
| Size of repair | Full width of carriageway and best value over larger distances. |
| Key features of the treatment | |
| Delivery time | Can require up to one day for the new surface to cure. |
| Carbon | 1.508 kgCO2e/m2 |
| Weather | Typically done in warmer months suitable for asphalt application. |
| In-situ recycling | £12-20 per m2 |
|---|---|
| Description |
The existing damaged road surface is pulverised, mixed with cement or bitumen and then relayed into a new road base. The base layer may need to be left overnight to harden before a surface dressing is applied. Can be shallow (retread-80mm), medium (150mm), or deep recycling (325mm) |
| Benefits | Significant cost savings compared to conventional resurfacing or reconstruction. Lower carbon impact by cutting waste and or need to heat materials. Adds a bound, base layer to poor or failing construction in roads. Can import coal tar contaminated material – saving £150 per tonne compared to taking to licensed tip |
| Cost | £12-20 per m2 |
| Where appropriate | In-situ recycling is best suited for large schemes, end-of-life treatments with extensive defects or degradation. It requires specialised equipment and is less suitable for urban areas due to dust, large machinery and the presence of underground structures. |
| Which roads are suited for this treatment? | |
| Highway condition | Near end-of-life roads with extensive deterioration. |
| Traffic level | All traffic levels. |
| Size of repair | Full width of carriageway and best value over larger distances. |
| Key features of the treatment | |
| Delivery time | The road is typically closed for 1-2 days during the process as the base layer must be left overnight before surface dressing applied. The recycled bound layer can be open to traffic for access purposes. |
| Carbon |
Low emissions due to recycled existing material, reduced transport needs and it being laid cold. Medium 150mm – 4.8 kgCO2e/m² Deep 250mm – 13.3 kgCO2e/m² Deep 250mm with low carbon cement alternative – 7.8 kgCO2e/m² |
| Weather | Needs dry weather during application. |
| Ex-situ recycling | |
|---|---|
| Description | Planed material is removed to a treatment site where it is screened, crushed and mixed. Material is cold mixed with a bituminous material to produce a CRBM - cold recycled bound material, which can then be transported back to site and laid. Recycled material can be mixed with cement to produce cement bound products. |
| Benefits | Repurposes existing asphalt materials to produce a low carbon replacement asphalt layer, offering significant financial savings. Can import coal tar contaminated material – saving £150 per tonne compared to taking to licensed tip. Less reliance on quarried aggregates. Less risk to installation teams. |
| Cost | Significantly less compared to new asphalt. |
| Where appropriate |
This is best suited for end-of-life roads where significant defects exist and which require replacement. A nearby site will be needed to set up for stockpiling planings, mixing plant, and vehicle movements.
|
| Which roads are suited for this treatment? | |
| Highway condition | Near end-of-life roads with large levels of deterioration. |
| Traffic level | All traffic levels. |
| Size of repair |
Full width of carriageway and best value over larger distances. Can also be used to produce localised patching materials. |
| Key features of the treatment | |
| Delivery time | Can batch out between 20 to 1500 tonnes in a single shift. The road is typically closed for up to a single day. |
| Carbon | Recycled material offers 70–74% reduction in CO2 emissions compared to traditional hot mix asphalt. |
| Weather | Needs dry weather during application. |
Note: The cost of raw materials is low, but the overall cost of crack sealing is highly variable due to a number of factors such as labour costs, the number of jobs delivered in a shift. Because of this, it is advisable to consult with local contractors or highway maintenance professionals.
Case studies
Key questions for councillors to ask of officers
In this section we’ve provided some examples of the type of question you might wish to ask officers to understand the situation in your area and consider the case for exploring new opportunities. We’ve grouped these questions into five categories.
Strategy and policy
- What preventative treatments does our council use?
- Have we considered trialling any other techniques?
- How does our maintenance strategy link to our wider priorities? – e.g. active travel, economic growth, accessibility, net zero.
- What are our key asset management strategies and policies? What should I know about them?
Planning
- How do we determine which roads should be prioritised?
- What evidence do we consider to determine which treatment to deploy on a particular road?
- To what extent do we consider carbon emissions in these decisions?
- When do we set our future plans for preventative maintenance?
- How do we ensure we are an intelligent client, recognising that treatments and techniques are advancing at pace and interventions must be appropriate to our network?
- How can councillors best engage in these decisions?
Funding
- How do we determine the balance of funding between preventative and reactive maintenance?
- When is our next decision point on allocations?
- Is there a good value-for-money case for undertaking a short-term investment programme (funded through borrowing or additional funds from the council) that gets the network back to a “steady state”?
Delivery and quality
- How do we contract the delivery of preventative maintenance? Is this in-house or outsourced to contractors?
- To what extent does the council have control over where and how maintenance work is delivered?
- When is the next decision point on our approach to procuring maintenance work?
- Do we collaborate with any neighbouring highway authorities on maintenance contracting?
- How do we evaluate the quality of value-for-money of previous work?
- How are we ensuring continuous service improvement with our supply chain?
Communication with residents
- How do we communicate future work plans to residents?
- How do we communicate the importance of preventative maintenance?
- Do we explain why we’re delivering activity in a particular way?
- Can I support you in delivering any key messages to residents?
Links to wider reading
- RSTA/REA – The Case for Surface Dressing
- RSTA – Pothole Prevention Week
- RSTA – Carbon Emissions Guidance
- Blackpool’s Project Amber
- DfT/HMEP – Prevention and a better cure
4. Reactive maintenance
Despite councils’ best efforts to invest in preventative treatments, proactively maintain their road networks, and fix potholes as they appear, the condition of local roads in England continues to deteriorate. Even with ideal prevention plans and no funding constraints, reactive repairs will still be needed.
In the face of this growing backlog, councils must target their reactive maintenance strategies to ensure that resources are deployed effectively. While preventative maintenance remains the most cost-efficient approach, councils must also respond swiftly to emerging defects, such as potholes, surface failures, and structural weaknesses, to maintain road safety and usability.
This section of the guide aims to increase awareness of the different techniques and technologies that highway authorities can use to repair potholes and other defects effectively.
No “one-size-fits-all” solution
There is no universal best method for repairing road defects – different techniques are suited to different circumstances. Factors such as road type, traffic levels, budget constraints, and weather conditions influence the most appropriate treatment choice. While a "first-time right" solution – one that delivers a durable, long-lasting repair – is always desirable, councils may sometimes need to compromise based on immediate needs and available resources.
Factors to consider when choosing a repair method
When deciding how to address road defects, councils must balance cost, longevity, speed of repair, and the impact on road users. Key considerations include:
- Severity of the defect – deep potholes may require a more intensive solution than minor wear, though a high-risk issue may also necessitate a temporary fix to make it safe before a full solution can be delivered.
- Road condition and future investment plans – if a road is nearing the end of its useful life and is due a full replacement in the next few years, a council might decide to deliver a quick fix to the most severe potholes, rather than a long-lasting solution.
- Traffic levels – high-traffic roads require durable repairs, whereas less intensively used roads may allow for a lower-cost solution.
- Carbon emissions of treatment – some materials and techniques are more environmentally friendly, which may be a strategic priority for your council.
- Weather conditions – some techniques require good weather or no standing water in the pothole for the fix to be delivered.
- Supply chain and contracting approach – a council’s approach to contracting with its highways maintenance supply chain determines how much control a council has over how work is delivered. Some heavily outsourced contracts do not allow councils to specify where or how work is done.
- Budget constraints and wider pressures – unfortunately, sometimes councils simply have too many calls on limited resources – in their highways function and across the council – meaning a low-cost solution is the only option.
Treatments
In this section, we summarise four common reactive treatments, their benefits, and factors that councils might wish to consider when deciding how to repair a pothole. We cover:
- Hot asphalt patching
- Thermal patching
- Spray injection patching
- Cold lay material
- Screed patching
It is challenging to provide reliable, general estimates on the cost of each of these techniques, as they can vary more widely than preventative techniques, depending on a wide range of factors such as regional cost differences, the number of potholes addressed in a day, whether equipment is owned or leased, among others. Broadly speaking, thermal patching is the most expensive, followed by hot asphalt patching, spray injection patching, then cold lay material. However, this is a generalisation and will vary. You should engage officers and local suppliers to get a good estimate of costs.
Hot asphalt patching |
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Description |
Durable method for fixing potholes. First, the pothole is cleaned, and the edges may be squared for better adhesion. A sticky binder coat is applied, then hot asphalt is poured in layers and compacted to create a smooth, solid surface. Once it cools (usually within an hour), the repaired area is ready for traffic, providing a long-lasting fix. |
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Benefits |
This technique is highly versatile – it is quick to deliver, suitable for all locations, relatively long-lasting, and can be delivered in all seasons. |
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Where appropriate? |
Delivering a long-lasting repair on a high-traffic area. |
Which roads are best-suited for this treatment? |
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Traffic level |
Suitable for all locations and traffic levels. |
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Equipment |
Specialist equipment needed – binder sprayer, chipping spreader, roller. |
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Delivery time |
Varies depending on equipment used – c.10-30 minutes per pothole, allowing 250m2 per day. |
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Carbon |
Dependent on delivery approach, but higher than cold-lay approach due to use of materials and heating. |
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Weather |
Suitable for all seasons. |
Thermal repair patching |
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Description |
Like the “hot patching” approach, but rather than excavating existing material, heat is applied to soften the surface around the damaged area. New binder and asphalt is applied and compacted. This aims to deliver a very strong bond between the old and new material, eliminating any weak points where water could permeate the surface. |
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Benefits |
Delivers a hard-wearing repair due to strength of bond with existing surface and absence of joint between old and new material. Can be more aesthetically pleasing than hot asphalt patching, due to blend with existing surface. |
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Where appropriate? |
Delivering a long-lasting repair on a high-traffic area. |
Which roads are best-suited for this treatment? |
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Traffic level |
Suitable for all locations and traffic levels. |
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Equipment |
Specialist equipment needed – binder sprayer, infra-red heater or gas burner. |
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Delivery time |
Approximately 30 minutes per repair. |
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Carbon |
Energy required to heat surface (gas or infra-red), but existing material is recycled rather than excavated. |
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Weather |
Unsuitable for delivery during rain and very cold weather. |
Spray injection patching |
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Description |
This is a rapid repair method that uses a high-pressure machine to apply a mix of emulsion and aggregate directly into a pothole. Some machines use compressed air or a flame to clear and dry the pothole, before a coat of emulsion is applied to help the new material bond with the existing surface. Finally, new material is sprayed into the hole to create a new, smooth surface. |
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Benefits |
This technique is fast to deliver, allowing roads to re-open quickly. Trucks can navigate hard-to-reach areas, allowing repairs on rural roads where a hot patch repair may be challenging. |
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Where appropriate? |
Delivering rapid repairs on roads where a quick re-opening is required. |
Which roads are best-suited for this treatment? |
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Traffic level |
Most suitable for low-medium traffic. Can be intermediate solution in high-traffic areas, but repair is not as durable as hot asphalt patching due to the weaker bond with the existing surface. |
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Equipment |
Specialist spray injection machine needed. |
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Delivery time |
Rapid delivery, road typically reopened within an hour. 100-200 repairs per shift. |
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Carbon |
Dependent on delivery approach, but higher than cold-lay approach due to use of materials and heating. |
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Weather |
Suitable for all seasons. |
Cold lay material |
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Description |
There are different types of cold lay, but the traditional approach is for pre-mixed asphalt to be laid into the pothole and compacted with a roller or vehicle tyres. No heating is required, making it a quick fix. This is typically a temporary, emergency fix and can be applied quickly in wet conditions. |
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Benefits |
This technique is quick to deliver and can be delivered in all seasons, and at all times of day. |
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Where appropriate? |
Temporary emergency repairs until a longer-term solution can be delivered. |
Which roads are best-suited for this treatment? |
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Traffic level |
Relatively low durability of material means this best suited to low-traffic areas. However, can be a helpful emergency repair in high-traffic areas, to “make-safe” an urgent issue. |
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Equipment |
No specialist equipment needed. |
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Delivery time |
Very quick and can be driven on immediately. |
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Carbon |
Lower than hot application of material. |
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Weather |
Suitable for all seasons, can be applied in wet conditions. |
| Screed patching | |
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| Description | Any loose material is removed. The defective area is then taped off. A hot, pre-mixed, polymer modified mastic asphalt is poured and moved around the defective area. Some materials will require a scattering of aggregate on the surface, whilst others may already contain aggregates in the mixed material. |
| Benefits | Quick to deliver and can be carried out in dry conditions. Significantly higher outputs compared to conventional patching. |
| Where appropriate | Defects up to 40mm in depth. |
| Key features of the treatment | |
| Delivery time | Very quick application and can be driven on once cooled. |
| Carbon | 2.5 kgCO2e/m² |
| Weather | Best suited to dry conditions. |
| Location | All locations. |
| Equipment | Specialist boilers and mastic floats, shoes/boxes or hot irons can be used to apply (spread) the product |
Innovative plant and machinery
Investment in modern plant and machinery is improving how councils approach reactive highways maintenance. New technologies and machinery - such as the JCB Pothole Pro, the Roadmender, and the Bobcat – are significantly improving the speed and efficiency of road repairs. These innovations present a number of key benefits for councils, including:
- Faster repairs – advanced machinery can cut the time required to fix a pothole, enabling teams to complete more repairs per day. JCB estimate that the Pothole Pro can repair potholes four times faster than conventional methods.
- Lower costs per pothole – by working faster, councils can spread overheads such as labour and traffic management over a greater number of repairs, reducing the cost per defect.
- Improved worker productivity – mechanisation reduces the physical demands on workers, allowing them to complete more repairs safely and efficiently.
The primary benefit of improved productivity is that councils can fix more potholes, faster. This enhanced efficiency gives councils flexibility in how they allocate their resources:
- Reinvest in further repairs – councils could use the increased capacity to fix more potholes, improving overall road conditions.
- Shift focus to preventative maintenance – productivity gains in reactive work could free up resources to invest in preventative measures, reducing future defects.
- Achieve cost savings – some councils may choose to redirect savings to other budget pressures.
While modern machinery delivers clear productivity gains, councils must weigh the business case for investment carefully. The upfront capital cost of new equipment is significant, so decision-makers should assess:
- Productivity gains – will the machinery enable teams to fix enough additional potholes to justify the investment?
- Wider benefits – could better road conditions lead to lower compensation claims and reduced long-term repair costs?
- Current equipment condition – how does the new technology compare to the council’s existing fleet? Is replacement due regardless?
- Cost saving opportunities – some councils may be able to share machinery with neighbouring authorities or explore leasing options to reduce upfront costs.
Your council should also consider whether its approach to delivery gives it control over the adoption of modern machinery. Councils that directly manage their highways maintenance have greater flexibility to invest in and deploy new technology. Where services are contracted out, the ability to specify modern plant and machinery depends on the terms of the contract and the contractor’s willingness to invest in new equipment.
Case studies
Key questions for councillors to ask of officers
In this section we have provided some examples of the type of question you might wish to ask officers to understand the situation in your area and consider the case for exploring new opportunities. We have grouped these questions into three categories.
Strategy, policy and planning
- What is our maintenance backlog?
- How do we determine which potholes should be prioritised for remediation?
- What reactive treatments does our council use? Have we considered trialling any other techniques?
- How do we determine which treatment should be used to fix a particular pothole? What factors do we consider in this decision?
- How do we plan our work to maximise efficiency? eg. fixing numerous potholes in an area at one time.
- To what extent do we consider carbon emissions in these decisions?
- When can councillors engage in these decisions?
- How do we ensure we are an intelligent client, recognising that treatments and techniques are advancing at pace and interventions must be appropriate to our network?
Delivery and quality
- How do we contract the delivery of reactive maintenance? Is this in-house or outsourced to contractors?
- To what extent does the council have control over where and how maintenance work is delivered?
- When is our current maintenance contract up for re-procurement?
- What capital machinery does the council own? When would be an appropriate time to consider investment in new machinery?
- Do we collaborate with any neighbouring highway authorities on maintenance contracting?
- How do we consider quality vs cost in procurement decisions?
- How do we evaluate the quality and value-for-money of previous work?
- How are we ensuring continuous service improvement with our supply chain?
Communication with residents
- How do we communicate future investment plans to residents? Do we give residents an indication of when a particular pothole will be fixed or how high it ranks in the council’s priority list?
- What communication do we do with residents on past successes?
- Can I support you in delivering any key messages to residents?
Links to wider reading
- ADEPT – Potholes – a repair guide
5. Technology
Role of technology
The previous sections have described some of the different ways that highways can be treated, and the circumstances under which these options are most effective. However, making the right decision, and deciding which roads to prioritise, is a complex challenge. It requires councils to ask the right questions, have the right processes, and possess the right data to inform these decisions.
Innovative technology, including AI, can play a big role in supporting councils to solve this puzzle of delivering the right activity in the right place at the right time.
Councils use technology in a number of ways, including to scan the condition of the highway; analyse that data and plan how and where work should be delivered; allow residents to report issues in their area; and to communicate future planned work to residents, highlighting positive investment but also alerting them to potential disruption.
Use of these technologies has a number of benefits, including helping councils to solve the challenges described in the previous chapters of this guide; improving the productivity of highway teams; providing better data on emerging problems on the highway network; and improving communication with residents.
There are a wide range of technologies available, and this guide isn’t intended to assess the various merits of each. Instead, it will set out some of the key opportunities across the sector in general, and some case studies of how individual councils are using technology today.
Scanning
One of the key areas of technological innovation in the highways sector regards how councils are scanning the condition of the road network. Many councils across England are making use of AI-powered technology where cameras are mounted on cars patrol the road network to scan the surface and identify problems. These have a number of key features, including:
- Spotting the small early warning signs of problems (e.g. cracks) before they turn into serious problems.
- Diagnosing the extent of a problem (e.g. pothole depth) and providing recommendations on how to address the issue.
- Analysing the growth rate of any defects, to provide insight on when they might develop into serious problems.
Work management systems
This data is then fed into a work-management system, which help officers create a maintenance plan. AI systems can analyse this data and overlay constraints such as budget availability to recommend an optimal strategy.
This can help answer questions like: what remedial work is critical today? which roads are beginning to deteriorate and need preventative action? which technique is most appropriate? where is a particular road in its lifecycle and when should we act?
These offer councils a number of major benefits:
- Supporting them to solve the “right activity, right time, right place” puzzle – as discussed in chapter 2 of this guide, councils have an extremely challenging job to maximise the impact of their investment in the face of a number of constraints and headwinds. Technology can not only provide officers with high-quality data on the condition of the road but also help them analyse this data. This is a valuable tool in helping to ensure councils are effectively prioritising limited funding, to deliver the right treatments, in the right place, at the right time.
- Saving money by repairing potholes before they become critical – the Asphalt Industry Alliance’s 2025 ALARM survey found that the average cost of repairing a pothole as part of a planned programme was £58, but this rose to £82 for urgent reactive repairs.
- Improving the productivity of maintenance teams – car-mounted cameras scanning the roads can radically increase the productivity of inspection teams by allowing them to collect vast data on the condition of the highway in a relatively short period of time. Particular advantages can be felt when an initial scan can estimate the depth of the pothole, which allows officers to remotely decide if an intervention is needed. This saves significant time compared to a council receiving a complaint from a resident, sending an officer out to inspect the pothole, then sending out a truck to repair it. Instead, the team can progress straight to repair.
- Improving the safety of inspection teams and reducing disruption for drivers – inspection teams frequently need to undertake inspections on fast-moving and high-traffic roads. This can require them to stand close to high-speed traffic, close the road, or undertake expensive night-time inspections. Camera-based scanning can allow them to inspect these sorts of issues without having to leave the car or close the road.
- Optimising scheduling of works – one of the key advantages of work management systems is how they support officers and contractors to identify the optimal delivery strategy, packaging up issues that are in the same area to be delivered in one go. Furthermore, where scanning helps councils identify new defects at an earlier stage, they can provide advanced notice to their contractors of future jobs with a longer lead-in time. This helps contractors more efficiently plan their work.
- Communication with residents and councillors – highway maintenance issues are one of the most common areas of contact between residents and councillors, and councillors and officers. Technology can help reduce some of this burden by improving the pro-active communication and increasing the information that is publicly available. Digital tools can allow councillors and residents to easily see if a council is already aware of a problem and what future schemes are planned.
Key considerations to implement new technology
As with all digital transformation issues, one of the key considerations for councils when deciding to adopt a new technology should be how they will implement and use it. The decision to move to a new technology and system requires an investment of time and money, so it’s important to be aware of these issues and the implications for your council before taking a decision.
This section of the guide aims to set out some of the key issues that your council may wish to consider, with the aim of supporting your conversations with potential suppliers. The specifics will vary from council to council.
One of the key considerations is how a new technology (eg. scanning system) will integrate with the council’s existing systems and processes. Key questions here include:
- How will the data collected by the scanning system “talk to” the existing software that our highways team uses to manage our network?
- How will we use the data that the new system collects to inform our decision making process?
Your council should also consider what skills are needed to initially implement as well as use new technologies. Most technologies do not require highly technical skills beyond those that a highways officer would normally possess, with only short training course typically needed. However, this is a key issue to be aware of when deciding whether to invest in a new technology.
A related issue is understanding what support a supplier will provide to set up the new system, integrate it into the council’s systems, and maintain it on an ongoing basis. Some suppliers will offer councils the choice about whether the council runs the system, or if the supplier will manage it for them. There is no “best” option here, and it depends on the needs of your council. Key questions here include:
- What skills are needed to implement the new system?
- What skills are needed to use the software on an ongoing basis?
- What level of ongoing support will the supplier provide in case of problems?
- Is this training included in our purchase? What if new members of staff join?
- What digital capabilities does our council already possess?
Overall, there are a wide range of technological options available, each of which has its own strengths. We would recommend speaking to a number of suppliers to understand the different options, considerations such as those listed above, and also testing out different technologies where possible.
Case studies
Updated monitoring standards from DfT
It is timely to consider these issues, as DfT is changing the standards for how councils should monitor, analyse and report the condition of their roads. These new standards (known as PAS 2161) have a wide range of implications for the level of work that highway teams do in monitoring road condition, potentially increasing the breadth of the network that councils are required to scan and the amount of data they report to DfT.
However, good use of this has a number of advantages for highway authorities, so this change should be seen as an opportunity, rather than a new data reporting pressure to adapt to. Crucially, it removes the current requirement to use a technology called SCANNER to deliver this road condition monitoring. Instead, councils will be able to choose from a wide-range of DfT-approved suppliers. This opens up new opportunities for councils to use the latest, innovative technology, as explored in this section of the guide.
These changes will come into effect gradually over 2025 and 2026, with the first full reporting cycle under the new standards coming into effect in 2027.
Key questions for councillors to ask of officers
In this section we have provided examples of the type of question you might wish to ask officers to understand the situation in your area and consider the case for exploring new opportunities. We have grouped these into three categories.
Systems and processes
- How do we conduct our road condition monitoring?
- How do we factor the information collected through road condition monitoring into decision-making over maintenance plans?
- How do our maintenance teams carry out inspections? Can technology help us improve the safety and productivity of this work?
Innovation and change
- Has the council considered investing in any new and innovative technologies? What are the benefits this would provide?
- If we choose to adapt to a new system, does the council possess the technical skills to implement and use this technology?
- How will the new data collection requirements set out in PAS 2161 impact our council? What investment do we need to do to become compliant? Is this a good opportunity to consider new and innovative technologies?
- How do we ensure we are an intelligent client, recognising that technology is advancing at pace and interventions must be appropriate to our network?
Communication
Is there an opportunity to use technology to improve communication with residents? (e.g. online maps of problems and future investments).
6. Next steps and further information
This guide has covered some of the key decisions in a council’s approach to highways maintenance, but there are a wide range of other issues beyond the scope of this guide on which councillors may wish to engage their officers. These include the overall highways asset management strategy, policy, and plan; local priorities; allocation of budgets; the council’s contracting strategy; how the council monitors the impact of previous investment and learns from this; and how the council communicates with residents on its plans.
Throughout this guide we have provided links to wider resources where you can find more information of the various issues, treatments and technologies discussed in this guide.
There are also a number of industry groups which provide a wide variety of support and information for councils, including:
- Local Council Roads Innovation Group (LCRIG) – LCRIG is an organisation that brings together local and national government with the supply chain. LCRIG has published a wide range of information on different maintenance techniques and technologies and holds frequent events to share knowledge and best practice.
- Road Surface Treatments Association (RSTA) – the RSTA is a member organisation across local authorities and the supply chain, bringing together expertise on preventative and reactive maintenance techniques. They have published a large number of information packs on these, which are available on their website.
- Roads Emulsion Association (REA) – the REA is a UK trade association representing manufacturing businesses that supply a wide range of bitumen emulsion products used in highways, airfield and construction sectors. They have published a helpful complementary communications guide for councillors to help them explain preventative road maintenance to their residents.
- Association of Directors of Environment, Economy, Planning & Transport (ADEPT) – ADEPT is a membership based organisation with more than 100 local authority members. It is primarily aimed at supporting officers, but their website has a wide range of information on highways maintenance issues, and the team are readily available to discuss questions and issues.
- UK Roads Leadership Group (UKRLG) – UKRLG is a forum for local and central government to discuss highways issues. Managed by the Chartered Institution of Highways and Transportation, it is primarily focused on supporting officers and highways technicians, but their website has a large number of publications on a variety of topics across the sector and is a good starting point for wider reading. CIHT’s Improving Local Highways document is aimed at the sector as a whole, including recommendations for DfT, but is an accessible exploration of key issues.
- Quick reference one-page guides to different road treatments