Anthony Browne is MP for South Cambridgeshire, the Chair of the Conservative backbench Treasury Committee and a member of the Treasury Select Committee.
The most important political challenge of our age is not the growing mistrust between China and the West. Nor the future of AI. No, it’s potholes. Anyone sniggering hasn’t been knocking on doors. Even at the best of times, it is a running joke among MPs that all politics is about potholes. But with May local elections, the public anger about our pockmarked roads is at fever pitch.
In South Cambridgeshire, like constituencies across the country, it is the number one topic of conversation. National journalists in London ignore potholes because they barely touch the capital’s roads but, in the rest of the country, potholes adversely affect people every day of their lives. They are expensive and dangerous. Daily chats with neighbours are about potholes wrecking their tyres, wheels or entire cars. Facebook groups discuss how to claim compensation from the council.
Drivers get particularly angry because, like small boats, having cratered roads is a sign of state failure. Never mind getting the trains to run on time – we can’t even make our roads drivable. There is a clear mismatch between public and private interest: the state saves money by not repairing roads, and individuals pick up the costs. The same frustration happens every spring, as predictable as the winter frost.
Potholes are a world-wide phenomenon, but our climate means we are affected more than most. Each winter, our roads go through dozens of freeze-thaw cycles, enabling water to enter cracks, freeze and fracture the asphalt. But that means we should give the issue more attention than most. With the move to electric cars, so much heavier than petrol ones, potholes are going to get worse.
It is welcome that the Government has increased its national pothole repair fund to £700 million. But there is more to do than just more repairs.
The high level problem with potholes is that they are not taken seriously. There is a huge mismatch between the public anger and the political debate, which sees it as all rather embarrassing. There is a touch of the John Major cones hotline – looking ridiculous by taking a trivial issue seriously. No self-respecting national journalist would write about it, or editor make it the lead on the television news. Although questions are asked about potholes in Parliament, I cannot remember a full debate.
Part of the problem is: what do you say? Potholes are bad, and need filling in. It is just a question of money. The Asphalt Industry Alliance campaigns for new money for old solutions. According to the Alliance, 1.7 million potholes were filled last year.
But there is a big debate to be had about how we solve the pothole problem. As a policy wonk would say, we need an evidence-based, system-wide approach to solving it, starting with a root cause analysis.
Another way of putting it is that it is not beyond the realms of material science to invent road surfaces that do not predictably disintegrate every winter. We have our best brains advancing genomics and AI, but they are not stopping roads falling apart every year. Nor is it beyond the wit of officialdom to ensure that the best practice is spread among local authorities. The Government needs to prioritise it as a national challenge to solve. Spoiler alert: the ultimate goal is self-repairing roads.
We need to tackle the causes of potholes, to stop them occurring in the first place, and also make the repairs of potholes more rapid and cost-effective.
Secondary roads are particularly prone to potholes because they are constructed poorly, with asphalt on an unstable foundation. There will be no permanent solution to the potholes on these roads unless we have a programme of identifying and prioritising roads that need to be rebuilt rather than just repeatedly repatched. It is a long term programme, but will reap permanent benefits. The US Army Corps of Engineers’ Cold Regions Research and Engineering Laboratory has produced a 34 page primer on preventing potholes, and one of the key recommendations is better drainage to take water away quickly.
Many potholes are caused by poor repairs when utilities dig up roads. The Department for Transport recently announced an intelligent risk-faced enforcement regime on utilities firms to ensure they properly make good the roads. But there should also be a programme of installing ducting, particularly under key roads and new roads: with ducts, utilities can install and repair cables under a road without digging it up. It can be paid for by utility firms, but needs local authorities to co-ordinate.
Local authorities, including in Cambridgeshire, are adopting new equipment to speed up repairs, such as the “dragons” that have flamethrowers at the front. Earlier this year, JCB launched the Pothole Pro machine, which can fill a pothole in 8 minutes at a cost of £30. Stoke and Coventry City are reported to be pleased with it.
But the quality of repairs is variable, and often quickly disintegrate. In Denmark and Slovenia they have done extensive trials on the most enduring methods for repairs. We could learn a lot from the US Federal Highways Administration, which has guidance (“Materials and Procedures for Repair of Potholes in Asphalt-Surfaced Pavements”) recommending which repair types are best in what conditions – hot patching materials, cold patching materials, “throw and roll” or spray injection. The UK’s own Institute of Asphalt Technology has summarised some of the global findings. Only 20 per cent of the cost of repair is the materials and so, rather than doing cheap repairs, it is more cost effective in the long run to use longer lasting materials.
Material scientists are turning their attention to the problem. There is a lot of pothole research in China and, last year, scientists from Beijing university published an extensive paper in the Journal of Cleaner Production which concluded that the durability of cold patching materials could be greatly improved. The University of Minnesota is developing asphalt with one per cent magnetite iron ore in, which can just be put in the pothole and then fixed in place being heated with microwaves, making it much quicker in cold conditions.
Material scientists from Delft University in the Netherlands have been developing self-healing roads, by putting steel fibres in the asphalt. Running a big magnet over the asphalt, the steel fibres heat up, melting the asphalt, and closing the cracks. They have trialled it on 12 different roads, and estimate that the material is 25 per cent more expensive, but that it doubles the lifespan of the road. The US’s Ready Mixed Concrete Research and Education Foundation is experimenting with concrete with dormant bacteria in, which when they get moist produce calcium carbonate, automatically filling in cracks.
The UK spends £5 billion a year maintaining our roads. A small investment in better materials could help trim that annual bill. Local authorities can fill in potholes, but national Government can tackle the pothole problem. A national pothole taskforce could look at international best practice, ensure local authorities adopt best short term solutions with existing technologies, and help develop new technologies. It is great we want to be a science super-power, but we could also be a pot-hole superpower. It might not be exciting, but it would please the voters – and reduce their car repair bills.