Everyone agrees there is a pothole problem,
So why don't we fix it?
The majority view might point to money, or rather, the lack of it, as the main issue. It's no secret that underfunding plays a significant role in road maintenance problems. However, there are wide variations in highway quality under the same funding model. This suggests that some Local Highway Authorities (LHAs) are managing their investments more effectively than others.
Numerous studies into the issue make one thing clear: a long-term strategic approach is not only more cost-effective overall, but it also improves user experience and helps LHAs meet their statutory safety obligations.
So, what options do LHAs have once a road—whether a major thoroughfare, a private driveway, or a lane—starts showing potholes? The accepted 'best practice' method is as follows: cut out the defective surface, prepare it with a suitable bitumen primer, fill with well-compacted hot asphalt, and overband the joint.
But what's the catch? Hot asphalt patches are not ideal for small repair areas like private driveways or lanes. Cutting out is labor-intensive and generates waste material. Keeping the asphalt hot to achieve a quality repair is challenging, and the added need for lane closures during excavation makes this method unsuitable for emergency interventions in both public and private settings.
Safety concerns mean serious defects need to be made safe quickly, and that’s where delayed set asphalt comes into play. This product can be stored for a reasonable time and used to fill potholes without the need for extensive excavation, making it a practical solution for not just highways but also private driveways, lanes, and industrial parks.
However, delayed set asphalt has its drawbacks. The resulting repair tends to be weaker than the surrounding surface, and the joint is highly prone to failure, which is why these are considered temporary fixes at best. Ideally, they should be replaced with hot asphalt as soon as possible.
More recent developments include activated (2-part) mixes, which use an accelerant (often water) to rapidly harden the repair, allowing traffic to resume quickly. These products are often the only option in emergencies, especially when surface water is present. However, they can pose future problems, as they may be unsuitable for subsequent surface treatments. Additionally, being harder, they can create joint issues with the surrounding asphalt over time.
Here are some common patching problems that illustrate the challenges facing LHAs, private property managers, and facility operators alike, leading to a decline in surface quality and, ultimately, the need for complete road or surface replacement.
Small cut out repair.
This typical small patch repair gives all the appearance of a well completed repair. However, the longitudinal damage has not been arrested. The damaged area is now over double the original size. Effectively, any short-term gain (safety) has been lost and the repair represents a 100% waste of resources.
Delamination of surface dressing
If the undersurface is not adequately primed there is a danger of water penetrating and becoming trapped between the layers. As it appears here, a previous patch joint has broken through the surface dressing. The hydraulic action of vehicles has done the rest. Most LHA's wouldn't warrant an emergency repair on this type of defect, but prompt action will prevent serious damage later on.
Revisit to 'Throw and go' repair
This pothole appears to be the failure of the third intervention at this point. The initial repair on the right seems to be either a cut-out repair or a utility reinstatement. This originally had a sealed joint. This joint has failed resulting in an unprepared (no cut-out) repair being made. This also has failed and been patched with a second 'throw and go' repair. This repair has now failed, meaning we have yet another emergency intervention required.
Failed recent repair.
According to the reporter, this repair is only 6 weeks old. Judging by it's dark colour it would seem to be recent. The step in the cut out is a false economy as it creates a weak point that is already failing. However, the failure to deal with the clearly damaged surface either side of the repair means that this intervention is as much the problem as its cure.
Repair breakthrough seeding pothole
This repair has been monitored for a couple of years. Within 12 months of surface treatment a hairline crack appeared around the small repair on the right of the image. Over the next 2 years the crack has become more pronounced. Eventually the repair shed it's layer of surface treatment. Whilst remaining in-situ, a new pothole, larger than the original, is now present. As the Institute of Asphalt point out, most reactive repair mixes are not compatible with over dressing.
Post Repair Problems
The breakthrough pothole shown above was recently 'repaired' with a competitors cold applied material. The repair has lasted just ONE WEEK and has caused extensive further damage to the surface.
A tale of Two Repair Types
This image is a contrast in repair methods and outcomes. The left-hand repair is after 3 weeks. The right-hand repair after 3 years.
The left used a 'throw and go' approach following a multitude of complaints from the public, who not surprisingly, were far from happy with the 'repair'.
The right hand repair using Britmix, has provided a far superior surface, that has stood the test of time.
Small cut out repair.
This typical small patch repair gives all the appearance of a well completed repair. However, the longitudinal damage has not been arrested. The damaged area is now over double the original size. Effectively, any short-term gain (safety) has been lost and the repair represents a 100% waste of resources.
Delamination of surface dressing
If the undersurface is not adequately primed there is a danger of water penetrating and becoming trapped between the layers. As it appears here, a previous patch joint has broken through the surface dressing. The hydraulic action of vehicles has done the rest. Most LHA's wouldn't warrant an emergency repair on this type of defect, but prompt action will prevent serious damage later on.
Revisit to 'Throw and go' repair
This pothole appears to be the failure of the third intervention at this point. The initial repair on the right seems to be either a cut-out repair or a utility reinstatement. This originally had a sealed joint. This joint has failed resulting in an unprepared (no cut-out) repair being made. This also has failed and been patched with a second 'throw and go' repair. This repair has now failed, meaning we have yet another emergency intervention required.
Failed recent repair.
According to the reporter, this repair is only 6 weeks old. Judging by it's dark colour it would seem to be recent. The step in the cut out is a false economy as it creates a weak point that is already failing. However, the failure to deal with the clearly damaged surface either side of the repair means that this intervention is as much the problem as its cure.
Repair breakthrough seeding pothole
This repair has been monitored for a couple of years. Within 12 months of surface treatment a hairline crack appeared around the small repair on the right of the image. Over the next 2 years the crack has become more pronounced. Eventually the repair shed it's layer of surface treatment. Whilst remaining in-situ, a new pothole, larger than the original, is now present. As the Institute of Asphalt point out, most reactive repair mixes are not compatible with over dressing.
Post Repair Problems
The breakthrough pothole shown above was recently 'repaired' with a competitors cold applied material. The repair has lasted just ONE WEEK and has caused extensive further damage to the surface.
A tale of Two Repair Types
This image is a contrast in repair methods and outcomes. The left-hand repair is after 3 weeks. The right-hand repair after 3 years.
The left used a 'throw and go' approach following a multitude of complaints from the public, who not surprisingly, were far from happy with the 'repair'.
The right hand repair using Britmix, has provided a far superior surface, that has stood the test of time.