SUVs are making Britain’s potholes worse, say scientists

Engineers link reduced lifespan of roads to shift to heavier cars, some bought to navigate damaged surfaces

Drivers who choose SUVs are compounding the pothole problem, experts have warned, as research showed hundreds of thousands of people bought bigger cars to navigate damaged roads.

Scientists said the cumulative effect of increasing numbers of heavier vehicles was a contributory factor in Britain’s potholes getting worse.

SUVs made up more than half of the 2m new cars sold in the UK last year, and a smaller but growing proportion of the 7m secondhand cars sold.

Recent polling showed almost one in eight drivers in parts of the country, including London and Yorkshire, had chosen to buy an SUV or heavier car partly due to concerns about road conditions.

According to the Opinium research, carried out for Kwikfit, 6% of drivers nationwide said they had been influenced to buy or bought an SUV primarily because of the condition of roads, a proportion that doubled among those who had suffered damage to their vehicle.

However, experts said those buyers were contributing to the problem they seek to avoid; furthermore, their vehicle and would not be immune to damage.

While the primary reason for pothole formation remained the freezing and thawing of rainwater over wet winters, and the heaviest vehicles, such as lorries, were likely to cause immediate damage, the growing weight of cars was worsening road surfaces.

Dr Ali Rahman, an assistant professor of civil engineering at the University of Leeds, said “the rising prevalence of SUVs does exacerbate pothole formation, because higher axle loads increase surface stresses, crack initiation, and road wear. They contribute a secondary but growing share of the problem, especially in cities where the road network was not designed for heavier passenger vehicles.”

Prof Anna Goodman, of the London School of Hygiene and Tropical Medicine, said: “The typical SUV exerts around five times more force on the road than the typical passenger car. The dramatic shift to SUVs in the past 20 years – from 3% of cars on the road in England to over 30% – is expected to have played some role in increasing wear and tear damage.”

Prof Christian Brand, the emeritus professor in transport at Kellogg College, Oxford, said SUVs were typically 200-300kg heavier than hatchback or sedan cars. While a single truck could do as much damage as many cars, “the rapid growth in SUVs means their cumulative impact, particularly on urban roads with lighter construction, may not be negligible and is increasingly relevant for local maintenance pressures”.

The Institution of Civil Engineers has said that heavier vehicles – also including electric cars – are a factor in pothole formation and reducing the lifespan of roads.

London is considering imposing extra charges on large SUVs, mainly due to the added safety risk they pose to other road users, as well as the space they take up. Transport for London is conducting studies on their effects on safety and congestion prior to announcing possible measures.

A spokesperson for the mayor of London, Sadiq Khan, said: “As part of their research TfL will look at the full impact of the continued growth in size and weight of these large SUVs, including any impact they have on the state and condition of London’s roads.”

According to an annual industry estimate by the Asphalt Industry Alliance, a road repair trade body, the cost of fixing all potholes and local roads across England and Wales has reached a record £18.6bn.

Steve Gooding, the director of the RAC Foundation, said: “Is it any wonder people are turning to rugged off-road oriented vehicles with the shocking state of many roads? Big wheels with all-terrain tyres are a better bet for bouncing over potholes but rarely come with the smaller, lighter cars that drivers might otherwise choose as perfectly suitable for the trips they need to make.”

Jack Cousens, the head of roads policy at the AA, said: “Sadly, all vehicles are at the mercy of potholes – regardless of what someone is driving, potholes are causing damage.”