From family hatchbacks to luxury SUVs and electric vehicles, Britain’s cars are getting bigger, wider and heavier than ever before.

It’s a trend that is raising growing concerns among road safety experts, transport researchers and environmental campaigners.

Tech, trends and fashions are all playing their parts.

Shocking weight gains

While electric vehicles are often blamed for increasing vehicle weights because of their large battery packs, industry experts say the reasons behind “carspreading” are far more complex, with stricter safety regulations, changing consumer tastes, government emissions policies and advances in technology all contributing to larger vehicles.

Research by green transport campaign group Transport & Environment (T&E) found that since 2000, the average new car sold in Europe has grown by around 1.2cm longer, 0.5cm wider and 0.5cm taller every year.

This steady increase has transformed the size of modern vehicles.

If the trend continues, researchers warn cities could lose between 8.5% and 14% of on-street parking spaces by 2040, with London and Berlin each projected to lose around 100,000 parking spaces simply because larger vehicles occupy more space.

Lucien Mathieu, an analyst at T&E, said: “This relentless carspreading highlights one critical question: where do we stop? The linear trend is so clear.”

Key Facts: T&E Report – Ever-bigger? Car size at a crossroads

  • ‘Carspreading to wipe out roughly 1 in 10 on-street spaces across the UK.

  • London and other major cities risk losing up to 14% of on-street parking if car sizes keep increasing by 1.2 cm annually

  • ‘Ever bigger’ cars trend could kill 400 more road users annually by 2040, compared to ‘right-sizing’ scenario across the UK & EU.

  • By 2040, 40% more child pedestrians could be killed a year in collisions compared to ‘right-sizing’ across the UK & EU.

Read the full report here.

Not so sporting

The biggest contributor has been the explosion in SUV sales.

Buyers increasingly favour higher driving positions, larger boots and greater practicality, prompting manufacturers to replace smaller hatchbacks with crossovers that are wider, taller and significantly heavier.

Electric vehicles have further accelerated weight gain.

Large battery packs capable of delivering 250 to 400 miles of range can add hundreds of kilograms to a vehicle.

However, engineers point out that heavier cars were already becoming the norm long before widespread electrification.

Modern safety requirements have also played a significant role.

Today’s vehicles feature reinforced passenger cells, larger crumple zones, multiple airbags, and sophisticated driver assistance systems, including autonomous emergency braking, adaptive cruise control, and lane-keeping technology.

While these innovations have dramatically improved occupant protection, they inevitably increase weight.

Luxury expectations have grown, too.

Features once reserved for premium models – panoramic glass roofs, electrically adjustable heated seats, large touchscreen infotainment systems, powered tailgates and extensive soundproofing – are now commonplace across much of the market.

Building better

Some automotive engineers also argue that emissions legislation has unintentionally encouraged heavier vehicles.

Under previous European fleet CO₂ regulations, manufacturers producing heavier cars were allowed more generous emissions targets than companies building lighter vehicles, reducing the incentive to prioritise lightweight engineering.

Despite the growth in vehicle size, manufacturers have made impressive gains in efficiency.

Between 2004 and 2014, average vehicle weight in Europe increased by around 2% while average engine power rose by 13%, yet average CO₂ emissions fell by more than 30% thanks to advances in engine and transmission technology.

However, the shift towards larger vehicles is not without consequences.

Road safety organisations warn that heavier SUVs pose greater risks to pedestrians, cyclists and occupants of smaller cars in collisions due to their greater mass and higher front-end design. Larger vehicles also require more space to manoeuvre and can reduce visibility for other road users.

Hannah Budnitz, a researcher at the University of Oxford’s Transport Studies Unit, said: “Larger vehicles are more dangerous to other road users, take up more space and use more resources, both when they’re manufactured and to keep them in motion.”

She added that many parking spaces are no longer large enough for modern SUVs, meaning vehicles often overhang pavements or occupy two bays.

Parking the bus

Infrastructure is another growing concern.

Engineering research has long shown that road wear increases exponentially as axle loads rise.

The widely accepted “fourth power law” suggests that even relatively small increases in vehicle weight can significantly accelerate damage to road surfaces, contributing to rising maintenance costs.

Environmental experts also warn that larger vehicles consume more energy regardless of how they are powered.

Professor Brian Caulfield, transport researcher at Trinity College Dublin, said: “When viewed through a climate lens, larger vehicles require more energy, regardless of whether they are fossil fuelled or electric.

“The research suggests this added demand could be equivalent to the output of an extra 1,500 offshore wind turbines.”

He added that growing electricity demand from larger electric vehicles comes at a time when national grids are already under increasing pressure from electrified heating, transport and expanding data centres.

Some European governments have begun responding.

France now applies a weight-based purchase tax on the heaviest new vehicles, while Paris has introduced sharply higher parking charges for large SUVs. Other cities are considering similar measures to discourage oversized vehicles in urban areas.

Give and take

For consumers, larger cars undoubtedly bring benefits.

They offer greater practicality, more interior space, improved crash protection and, in the case of electric vehicles, batteries mounted low in the chassis that can improve stability and handling.

The challenge facing manufacturers is balancing these advantages with growing concerns about safety, infrastructure, energy use, and the environment.

Advances in lightweight materials, more energy-dense batteries and smarter vehicle design could eventually reverse the weight trend.

Until then, the love affair with bigger cars looks set to continue, bringing both undeniable benefits and increasingly difficult questions about the future of motoring.