A new study commissioned by Halfords has raised serious concerns about the safety of worn tyres.

Researchers are warning that driving on tyres at the legal limit could be more dangerous than using a mobile phone at the wheel.

Using a mobile at the wheel has itself been found to be as dangerous as driving over the drink drive limit.

Legal but not safe

The research, conducted by Professor Peter Wells, director of the Centre for Automotive Industry Research at Cardiff University, suggests that current UK tyre laws may not go far enough to protect drivers.

The study found that tyres worn to the UK’s legal minimum tread depth of 1.6mm, still sufficient to pass an MOT, can dramatically increase stopping distances, particularly at higher speeds.

At 70mph, a car fitted with tyres at the legal limit takes an additional 27 metres to stop compared with a vehicle on well-maintained tyres.

That equates to around six extra car lengths.

By comparison, using a mobile phone while driving increases stopping distance by around 15.5 metres, meaning worn tyres can have an even greater impact on braking performance.

In real terms, the research showed:

  • A car with good tyres stops in around 96 metres
  • With phone distraction: 111.5 metres
  • With worn (but legal) tyres: 123 metres

Professor Wells said the findings highlight a largely overlooked danger.

“The impact of worn tyres is generally worse,” he explained, adding that tyre performance “begins to become impaired long before they reach the legal limit.”

Rising safety concerns

The findings come amid evidence that tyre-related incidents are on the rise.

Government data shows that deaths or serious injuries linked to defective tyres rose from 147 in 2022 to 172 in 2024, underlining the growing scale of the problem.

Despite this, awareness among motorists remains low.

The study found that:

  • Only 7% of drivers believe worn tyres are more dangerous than phone use
  • Just 28% know the legal tread limit
  • Nearly 30% never check their tyres regularly

More than half of drivers surveyed said they were surprised to learn how much worn tyres affect stopping distances.

With budget tyres being a popular choice in these economically testing times, the stopping distance issues are even greater.

Calls for change

Experts are now questioning whether the UK’s legal tread limit is set too low.

Both Professor Wells and Halfords recommend replacing tyres at around 3mm of tread, rather than waiting until the legal minimum is reached.

Commenting on the findings, Halfords’ managing director of autocentres, Adam Pay, said: “The legal minimum shouldn’t be mistaken for a safety benchmark. When tyres reach that point, their performance is already significantly reduced.”

Road safety charity TyreSafe also backed the findings, with chair Stuart Lovatt describing the research as highlighting a “critical and often overlooked factor” in road safety.

He urged drivers to treat tyre maintenance with the same seriousness as mobile phone use behind the wheel.

The study has sparked renewed debate about how tyre safety is regulated and enforced in the UK.

While offences such as mobile phone use carry strict penalties, campaigners argue that worn tyres, despite their significant safety impact, receive less attention.

There is also growing public support for tougher rules.

Around 31% of motorists believe the legal tread limit should be raised, while more than half support stricter penalties for driving on worn tyres.

Hidden risk 

The research ultimately suggests that one of the biggest dangers on Britain’s roads may be hiding in plain sight.

Unlike distracted driving or speeding, worn tyres are often invisible to other road users, and sometimes even to drivers themselves.

As Professor Wells warned, the assumption that “legal means safe” may be putting motorists at risk.

With stopping distances significantly affected well before tyres become illegal, the study calls for a shift in both driver behaviour and policy.