Car bonnets becoming half centimetre higher every year, driving road danger fears – study

The bonnet height of new cars in the UK is increasing by half a centimetre a year, on average, driven by the growth in SUV sales, new research finds. The trend is part of the recent phenomenon of ‘carspreading’ where supersized SUVs crowd out space in towns and cities and are more dangerous in a crash. In tests conducted for the report by T&E, drivers in the highest fronted vehicles could not see children as old as nine standing in front.

New car bonnets were 83.7 cm high, on average, in 2024 in the UK – up from 76.9 cm in 2010, according to the report, which also covers the EU and Norway, and is the first to analyse bonnet heights at European level. The rise coincides with the steady increase of SUV sales from 12% of new UK sales in 2010 to to 63% last year. European and national laws do not limit bonnet height.

In crashes, high-fronted cars typically strike adult pedestrians above the centre of gravity, often first hitting vital organs. The higher the vehicle front the more likely a person will be knocked under the car, rather than pushed to the side, at speeds of up to 50 km/h. One study, based on crashes involving 300,000 road users in Belgium, suggests that a 10 cm increase in bonnet height (from 80 cm to 90 cm) raises the risk of death by 27% for pedestrians, cyclists and other vulnerable road users.

High bonnets also reduce drivers’ vision of other road users. Tests commissioned by T&E find a driver of the highest fronted model on UK roads, the Ram TRX, is unable to see children aged up to nine standing directly in front. A Land Rover Defender driver cannot see children aged up to four and a half.

Anna Krajinska, UK T&E Director, said: “Higher bonnets are a danger to pedestrians, cyclists and people in regular cars. It’s impossible to see children standing in front of some of the highest fronts. The growing trend towards SUVs means this problem will only get worse unless we set limits.”

T&E and the Clean Cities Campaign called on the UK and the EU to cap bonnet height by 2035 as part of a reform package to limit ever-expanding car dimensions. For bonnets, the study recommends a maximum height of 85 cm for further study. The long lead time to 2035 would help minimise disruption to existing production and designs. National and city authorities should also make taxes and parking charges fairer by linking them to the weight and size of vehicles. Across most of Europe, weight is the best available proxy until law-makers make size data more accessible.

T&E UK and the Clean Cities Campaign back the SUV Alliance manifesto for safer, fairer streets and are calling on the Government to introduce stricter regulation on vehicle design to reverse the trend towards larger bodies and higher bonnets on cars.

Oliver Lord, UK Head of Clean Cities Campaign said, “Carspreading is out of control and children’s lives are at risk. The failure to regulate supersized SUVs is leaving city leaders with little choice but to stand up and do all they can to discourage unnecessary and dangerous vehicles on our streets.”