Can oversized cars be cut down to size?

Carspreading: SUV Alliance calls for fairer parking charges and taxes on oversized cars based on their size and risk they pose to vulnerable road users and pedestrians

The growing popularity of large cars means that more than 1 million of the vehicles sold in the UK each year are now too big to fit a typical urban car parking space.

Guidelines state that on-street parking bays should have a minimum width of 1.8m, and length of 4.8m which is the typical size in urban areas. The problem is that supersized sports utility vehicles (SUVs) now regularly measure more than 1.8m wide and 4.8m long – a process some refer to as ‘carflation’.

Research also shows that SUVs are getting heavier and larger: 400kg heavier in the last seven years, according to research by Autocar.

SUVs are continually becoming longer, wider and heavier. They are also becoming ever more popular. Around 4.6 million SUVs have been sold in the UK since 2021, according to researchers at Clean Cities, a European network of organisations calling for healthy and climate-friendly transport in cities.

Clean Cities is worried that SUVs are crowding out space in towns and cities, causing more road wear and more likely to cause fatal injuries for children, cyclists and those driving smaller cars. Campaigners call this phenomenon ‘carspreading’.

As cars get bigger, so do the risks. People hit by larger cars when walking or cycling are far less likely to survive. According to a Europe-wide study, which included the UK, when vehicles are 300kg heavier, the risk of fatal injuries is 30% higher for vulnerable road users. Pedestrians and cyclists are also 30% more likely to be killed if they’re hit by a car with a bonnet that’s 10cm higher than average. The research was conducted by the Belgian Road Safety Institute. The data analysed 300,000 car passengers and vulnerable users over four years.

In a collision between a 1,600kg car and a lighter 1,300kg car the risk of fatal injury reduces by 50% for the occupants of the heaviest car and increases by almost 80% for the occupants of the lighter car. In the event of an increase in mass of 300kg, the risk of fatal injuries is also 30% higher for vulnerable road users.

The SUV Alliance

A coalition of charities and campaigners are now working against the ‘carspreading’ phenomenon. The campaign includes organisations such as Clean Cities, AdFree Cities and Mums for Lungs.

The SUV Alliance is calling fairer taxes that favour lighter and more appropriately sized cars. Bigger cars take up a lot more space, but the cost of parking stays the same. The alliance is thus calling for parking costs in cities to be based on the size of a car.

The alliance’s manifesto argues city leaders should make parking policies fairer by varying costs based on a vehicle’s size.

At the national level, government should adjust taxes in favour of lighter and more appropriately sized cars. There should also be maximum width, length and height limits for new cars. Current regulations allow for cars to be built as wide as a truck.

The campaign advocates for a national ‘tobacco-style’ ban on SUV advertising (including hybrid and electric SUVs) in outdoor spaces. The alliance argues that advertising is driving demand for larger SUVs, rather than demand creating the supply.

The SUV Alliance wants to see mandatory ‘eco-scores’ published for all new electric vehicles, combining engine efficiency and lifecycle CO2 emissions, to make clear their impact on the planet.

The campaign also wants to empower local authorities to introduce ‘progressive parking tariffs’ on heavier, bigger, and more polluting vehicles, due to their climate impact and danger for road users. It cites examples like Paris – and in England, Bath (Somerset) and Islington (London) – which have introduced increased parking charges for larger vehicles.

Oliver Lord, UK head of Clean Cities, says: “Cars are getting bigger every year, while our streets are not. We need carmakers to prioritise normal sized cars that can be parked more easily and are less dangerous to people walking around. It’s only fair if you want to buy a massive SUV that you should expect to pay more for the space it takes up.”

Jemima Hartshorn, a parent who set up the Mums for Lungs group, says: “There is a real problem on our streets, the cars are getting bigger and bigger, and more dangerous. The chance of a road death or serious injury if you collide with one of these big SUVs is huge. Of course we want everyone including young children to cycle on our roads, but it is unsafe these days.”

The SUV Alliance encourages supporters to share the manifesto with local MPs and councillors to introduce anti-SUV policies.

The SUV Alliance formally launched its manifesto at an event in the House of Lords on 26 March. The reception was hosted by Green peer Jenny Jones and brought together national policymakers and representatives of local councils.

Baroness Jones said: “Sales of SUVs have leapt up in the last two decades, yet many urban streets and car parking bays are simply too small to accommodate the increasing girth of these vehicles. I like what Paris has done to discourage their use, by charging the largest cars as much as three times more to park. In the UK, Bath and Islington councils have introduced similar measures. The government should encourage other councils to replicate these efforts.”

An expert view

A new UK academic paper shows that heavier cars are more likely to be involved in fatal collisions and average car weight in the UK is increasing. This may lead to a rise in fatal collisions if the trend continues, the academics warn. 

Reducing car weight could mitigate the severity and frequency of collisions, while the academics suggest that policy makers could consider “taxation on heavier cars” and that “local authorities could adjust parking policies to charge higher fees for heavier cars.

The study, led by civil engineer Ruth Carlson with a co-author from the University of Huddersfield, is based on preliminary findings with the full paper out later this year.

Solutions to a taxing problem

New taxes could reap significant rewards for HM Treasury and the Department of Transport, predicts the alliance. As well as the additional revenue, discouraging sales of heavier cars could reduce road maintenance costs. According to ‘the fourth power law', a formula developed by US Highway Officials, the damage done by a vehicle to a road surface is proportional to the fourth power of its axle weight.

A two-tonne SUV therefore does 16 times more damage than a one-tonne car, says the SUV Alliance. The potholing of road surfaces is even worse when it rains because heavier vehicles create much stronger hydraulic pressure, forcing water into any flaws and breaking up the road surface.
www.suv-alliance.org.uk