New cars are getting too big for British roads while “spilling out of parking spaces”, according to new research.

Groups backing the research say bigger cars are less sustainable, make our roads more dangerous and take up more space

Eco campaign group Transport & Environment (T&E) says more than half of new cars sold in 2023 were too wide for the minimum specified on-street parking space (180cm) in major UK cities.

The average width of new cars expanded to 180.3cm in the first half of 2023, up from 177.8cm in 2018, the T&E research found. On average cars were revealed to be getting 1cm wider every two years.

The problem is worse for large luxury SUVs, which measure around 200cm wide and leave very little space. Growing width of these cars is going to exacerbate those pressures. A similarly densely populated city, Paris, will vote on tripling parking fees for SUVs on 4 February.

New cars in the UK are subject to the same maximum width, 255cm, as buses and trucks. T&E said that unless the UK width limit for cars is reviewed, large SUVs and pickups will continue to expand to the cap meant for heavy-duty vehicles.

As well as bringing parking issues, the trend towards wider vehicles is reducing the road space available for other vehicles and cyclists while parked cars are further encroaching on footpaths. The wider designs have also enabled the height of vehicles to be further raised, despite crash data indicating a 10cm increase in the height of vehicle fronts carries a 30% higher risk of fatalities in collisions with pedestrians and cyclists.

The UK has inherited EU legislation on vehicle width, which has not changed since Brexit.

Now, T&E UK is urging a mandated width limit for cars be implemented with an approval process that is consistent with EU regulations, to reduce compliance costs for carmakers. It’s calling for the regulations to come into effect from 1 January 2030, which would be consistent with the changes to EU regulations proposed by T&E.

Richard Hebditch, UK director for the group, said: “The trend of cars getting wider has been progressing for decades and that trend will continue until the UK sets stricter limits. Currently we allow new cars to be as wide as trucks. This has meant our roads are now home to big SUVs and American-style pickup trucks that are parking on our footpaths, endangering pedestrians and cyclists and making everyone else on our roads less safe.”

Sarah McMonagle, director of external affairs at Cycling UK, added: “We need government action to stop motor manufacturers fuelling our addiction to ever-more obese cars. Bigger cars are not better, they’re less sustainable, make our roads more dangerous, and take up more space, increasing congestion.”

And Leo Murray, co-director of climate charity Possible, commented: “This analysis shows that the profit-driven trend to autobesity can be measured in cars’ expanding waistbands as well as their increasing weight, and the negative impacts have become impossible to miss on any crowded inner-city street, with new SUVs spilling out of their parking spaces and blocking footways and other vehicles.

“Previous research has found that ‘downsizing’ policies to limit the size and weight of new private cars could be surprisingly effective at driving down carbon emissions too, so we are delighted to join T&E’s call for a new width limit on UK car sales from 2030.

“In the meantime, forward-looking local authorities can help by only issuing on-street residential parking permits for cars that actually fit inside the spaces provided.”