Heavy EVs are not the main cause of potholes
Electric cars and large SUVs are getting heavier, but a recent analysis suggests they are not the main reason roads are deteriorating. British road-engineering experts interviewed by Autocar point to far more influential factors: heavy goods vehicles, water penetrating the road surface, freeze-thaw cycles, heatwaves and years of deferred maintenance.
Passenger cars really are getting heavier
According to Autocar’s analysis, the average kerb weight of new cars has risen by almost 400 kg in nine years, from 1,553 kg to 1,947 kg. The 73 cars tested by the publication in 2025 averaged 2,024 kg, with SUVs and electric cars dominating the sample.
The increase in weight is therefore real. In EVs, a substantial share of the extra mass comes from the traction battery. Large SUVs, meanwhile, are longer and wider and tend to require stronger body and chassis components.
It is easy to conclude that heavier cars therefore cause more road damage. In physical terms that is true, but the scale of the effect is very different between a passenger car and a heavy lorry.
Axle load changes the equation
Ali Rahman, a civil-engineering researcher at the University of Leeds, told Autocar that pavement damage rises very rapidly as axle load increases. The so-called fourth power law used in road engineering means, in simplified terms, that doubling the axle load can increase its damaging effect on the road surface by roughly 16 times.
That is why the difference between a 1,800 kg combustion-engined car and a 2,100 kg EV is not remotely comparable with the difference between a passenger car and a multi-axle heavy goods vehicle.
According to Rahman, HGVs are responsible for the majority of road damage caused by traffic loading. A single heavy lorry pass can have an effect on the pavement comparable in scale to thousands of passenger-car passes. From an engineering standpoint, it therefore makes little sense to single out EVs or SUVs as the main cause of road deterioration.
That does not mean passenger-car weight is irrelevant. If the entire vehicle fleet becomes heavier, the load placed on roads increases too. The key issue is the proportion of the overall impact.
Potholes are created by water, temperature and traffic working together
Britain’s climate provides almost ideal conditions for potholes to form. Water seeps into microscopic cracks in the asphalt, temperatures fall below freezing and the water expands as it turns to ice. That weakens the structure of the road surface.
Bitumen also becomes more brittle in cold weather. When vehicles pass over a weakened section, the material begins to break up and a small crack can develop into a pothole. During winter, the cycle can repeat several times in a relatively short period.
At the other extreme is heat. High temperatures soften the bituminous binder and make the road surface more vulnerable to deformation under heavy loads. Climate change and more frequent temperature extremes therefore place additional stress on road structures.
Britain faces an £18.62 billion road-maintenance backlog
The most striking figure, however, has little to do with vehicle weight and everything to do with the maintenance deficit.
According to the Asphalt Industry Alliance’s 2026 ALARM survey, local roads in England and Wales require around £18.62 billion — approximately €21.5 billion — of work to bring the network to a condition where it can then be maintained cost-effectively. At the current rate of progress, clearing the backlog would take around 12 years.
The remaining structural life of the roads is even more telling. An estimated 16 per cent of the local road network has less than five years of structural life remaining, covering more than 52,000 km of roads.
Around 1.9 million potholes were repaired in England and Wales in 2025, equivalent to more than 5,200 repairs a day. At the same time, the average local road is fully resurfaced only about once every 97 years.
EV weight still matters
The experts’ conclusions should not be taken to the opposite extreme by claiming that the growing weight of passenger cars has no effect on roads. It does.
A heavier car places greater loads on its tyres, suspension, brakes and the road surface. Accelerating more mass also requires more energy. An EV can recover some braking energy through regeneration, but that does not repeal the laws of physics.
Improving battery energy density is therefore becoming increasingly important for the car industry. A smaller, lighter battery reduces energy consumption, improves handling and cuts material use. Compact EVs already show that an all-electric powertrain does not automatically mean a two-tonne kerb weight. The Dacia Spring, for example, weighs less than a tonne, while the Renault Twingo E-Tech comes in at around 1,200 kg.
Britain’s pothole problem is a useful reminder of why simple scapegoats can be misleading in complex technical issues. The increasing weight of EVs and SUVs deserves attention, but a heavy passenger car driving over a road is not, on its own, what creates potholes. When years of underinvestment are combined with water, freezing temperatures, heat and heavy goods traffic, the extra mass of passenger cars is only one part of a much larger equation.
Passenger cars really are getting heavier
According to Autocar’s analysis, the average kerb weight of new cars has risen by almost 400 kg in nine years, from 1,553 kg to 1,947 kg. The 73 cars tested by the publication in 2025 averaged 2,024 kg, with SUVs and electric cars dominating the sample.
The increase in weight is therefore real. In EVs, a substantial share of the extra mass comes from the traction battery. Large SUVs, meanwhile, are longer and wider and tend to require stronger body and chassis components.
It is easy to conclude that heavier cars therefore cause more road damage. In physical terms that is true, but the scale of the effect is very different between a passenger car and a heavy lorry.
Axle load changes the equation
Ali Rahman, a civil-engineering researcher at the University of Leeds, told Autocar that pavement damage rises very rapidly as axle load increases. The so-called fourth power law used in road engineering means, in simplified terms, that doubling the axle load can increase its damaging effect on the road surface by roughly 16 times.
That is why the difference between a 1,800 kg combustion-engined car and a 2,100 kg EV is not remotely comparable with the difference between a passenger car and a multi-axle heavy goods vehicle.
According to Rahman, HGVs are responsible for the majority of road damage caused by traffic loading. A single heavy lorry pass can have an effect on the pavement comparable in scale to thousands of passenger-car passes. From an engineering standpoint, it therefore makes little sense to single out EVs or SUVs as the main cause of road deterioration.
That does not mean passenger-car weight is irrelevant. If the entire vehicle fleet becomes heavier, the load placed on roads increases too. The key issue is the proportion of the overall impact.
Potholes are created by water, temperature and traffic working together
Britain’s climate provides almost ideal conditions for potholes to form. Water seeps into microscopic cracks in the asphalt, temperatures fall below freezing and the water expands as it turns to ice. That weakens the structure of the road surface.
Bitumen also becomes more brittle in cold weather. When vehicles pass over a weakened section, the material begins to break up and a small crack can develop into a pothole. During winter, the cycle can repeat several times in a relatively short period.
At the other extreme is heat. High temperatures soften the bituminous binder and make the road surface more vulnerable to deformation under heavy loads. Climate change and more frequent temperature extremes therefore place additional stress on road structures.
Britain faces an £18.62 billion road-maintenance backlog
The most striking figure, however, has little to do with vehicle weight and everything to do with the maintenance deficit.
According to the Asphalt Industry Alliance’s 2026 ALARM survey, local roads in England and Wales require around £18.62 billion — approximately €21.5 billion — of work to bring the network to a condition where it can then be maintained cost-effectively. At the current rate of progress, clearing the backlog would take around 12 years.
The remaining structural life of the roads is even more telling. An estimated 16 per cent of the local road network has less than five years of structural life remaining, covering more than 52,000 km of roads.
Around 1.9 million potholes were repaired in England and Wales in 2025, equivalent to more than 5,200 repairs a day. At the same time, the average local road is fully resurfaced only about once every 97 years.
EV weight still matters
The experts’ conclusions should not be taken to the opposite extreme by claiming that the growing weight of passenger cars has no effect on roads. It does.
A heavier car places greater loads on its tyres, suspension, brakes and the road surface. Accelerating more mass also requires more energy. An EV can recover some braking energy through regeneration, but that does not repeal the laws of physics.
Improving battery energy density is therefore becoming increasingly important for the car industry. A smaller, lighter battery reduces energy consumption, improves handling and cuts material use. Compact EVs already show that an all-electric powertrain does not automatically mean a two-tonne kerb weight. The Dacia Spring, for example, weighs less than a tonne, while the Renault Twingo E-Tech comes in at around 1,200 kg.
Britain’s pothole problem is a useful reminder of why simple scapegoats can be misleading in complex technical issues. The increasing weight of EVs and SUVs deserves attention, but a heavy passenger car driving over a road is not, on its own, what creates potholes. When years of underinvestment are combined with water, freezing temperatures, heat and heavy goods traffic, the extra mass of passenger cars is only one part of a much larger equation.
