Keeping the water out: what ALARM 2026 tells us about prevention at the kerb

The Asphalt Industry Alliance's ALARM 2026 survey makes sobering reading. The backlog of local road repairs in England and Wales has reached a record £18.62 billion, despite the biggest rise in highway maintenance budgets in the survey's history. Read alongside what we see at the kerb edge every day, it also points to one of the cheapest ways to start turning that round.

More money, but only marginal gains

Councils' highway maintenance budgets rose by 17% last year, to an average of £30.5 million each, and carriageway budgets by 20%. Yet the share of roads in good condition rose by only two percentage points, and one mile in every ten, around 20,400 miles, is still likely to need maintenance within a year. The annual shortfall in carriageway budgets actually grew, to £1.37 billion.

As one highway official told the survey: "We've been underfunded for so long that even the increase we've seen this year is not enough for the public to see a visual improvement."

That matters. If more money alone is struggling to move the dial, the question becomes where each pound does the most good.

Water is the common enemy

ALARM is clear about what is driving the decline. Last winter was one of the wettest on record, and the report explains how water penetrates existing cracks and defects, leading to potholes that "proliferate over time". Resurfacing matters, it says, because it keeps a weatherproof seal on the road and guards against water ingress and freeze-thaw.

From the kerb side, we keep finding where much of that water is being held. Detritus, the soil, grit and leaf litter that builds up along kerbs, acts like a damp sponge, holding water against the edge of the tarmac long after the rain has stopped. It feeds weeds whose roots open up joints. And it washes into gullies and blocks them, so water cannot get away.

The council data backs this up. In one city council's records, streets with blocked-gully complaints had 2.3 times as many potholes as other streets, and the gap widened in winter, pointing to water and frost rather than traffic.

The part of the budget ALARM doesn't measure

ALARM focuses, rightly, on the carriageway budget: the money spent on the road surface and structure. It explicitly leaves out cyclical work such as sweeping and grass cutting.

But that is exactly where much of the cheapest protection for the carriageway sits. Sweeping, gully cleaning and weed control are usually funded and managed separately from road repairs, often by different teams. The work that keeps water away from the road edge is rarely counted as protecting the road at all.

The effect is sharpest on residential streets. Unclassified roads make up 61% of England's local network, and ALARM reports they are resurfaced on average only once every 123 years. These are also the streets where parked cars stop sweepers reaching the kerb, and where detritus builds up fastest.

ALARM's own figures show prevention pays

• Planned beats reactive. A pothole filled as planned work costs £63.11; a reactive repair costs £93.79.
• Too much is still spent reactively. Reactive work takes 25% of carriageway budgets, against the 18% councils consider appropriate. Closing that gap would free £203 million a year for proactive work.
• Councils are already moving towards preservation. The share of the network treated to prolong its life rose by 47% last year, to 4.4%.
• A steady state is cheaper. Councils say that, with the backlog cleared, keeping roads in good condition would cost £1 billion a year less.

The AIA's chair, David Giles, calls for a shift to "proactive programmes that prevent potholes forming in the first place". We agree, and would add one step even earlier in the chain. Removing detritus while it is still 10 to 25 mm deep, before weed roots anchor into the surface, costs under £10 per square metre. Once roots have anchored and the edge starts to fail, repairs cost £75 to £150 per square metre.

Claims are down, but still costly

Road user compensation claims fell by 32% to an average of 279 per authority, with £31.0 million spent on claims across England and Wales, including £15.1 million in staff costs. Almost all of them, 99%, relate to potholes on roads, footways or cycleways. Every pothole prevented is a claim that never arrives.

What councils can do now

1. Treat kerb edges and gullies as part of protecting the carriageway, and include them in highway asset management plans.
2. Measure detritus depth alongside road condition data. With PAS 2161 bringing better condition reporting from 2026/27, it is the right moment to add the kerb edge.
3. Clear kerb lines and gullies before winter, so water can get away when it matters most.
4. Use the right machine for residential streets. Pedestrian sweepers and weed brushes can reach the kerb where larger sweepers cannot.
5. Link the budgets, so savings in reactive repairs can fund the prevention that creates them.

The bottom line

The AIA is right that lasting improvement needs sustained, long-term funding. But every pound spent on resurfacing goes further if the water can get away. Keeping kerbs and gullies clear is one of the cheapest ways to protect the investment councils are now making.

To talk about prevention on your network, or to arrange a demonstration, contact Kersten UK.

Source: Figures from the AIA's ALARM survey report 2026 (AIA ALARM 2026), unless otherwise stated. Kerb-edge cost figures from the Bracknell IWM Trial and published highway maintenance benchmarks.