Drivers in the UK are waiting until they are told they need new tyres before changing badly worn ones.
A survey shows 3.6 million drivers say they only have new tyres fitted to their car when the tread fails the MOT test.
Worn tyres require 40% more distance to stop from 50mph in dry conditions, which is equivalent to eight car lengths. This increases even more on wet roads.
By leaving the fitment of new tyres to their car until the MOT, these drivers are risking not only lives but a £2,500 fine and three penalty points on their driving licence.
The survey by Kwik Fit points out the legal minimum tread depth is 1.6mm across three-quarters of the tyre's width.
However, it is wise to switch to new tyres before the tread wears down to this minimum to preserve the braking, handling and steering of your car at its best.
Roger Griggs, communications director at Kwik Fit, said: 'With vehicles being increasingly sophisticated in monitoring their own maintenance intervals, drivers are often leaving it to their cars to warn them of potential issues.
"Motorists should realise that responsibility for vehicle health and safety lies directly in their hands. Without proper care, motorists could land themselves either in legal trouble or in an incident on the road.
"Tyres should be the number one priority for drivers - after all, they are the only part of a car which keeps it on the road. Even though at 1.6 millimetres of tread a tyre is legal, it will not have much grip on the road and travelling in adverse weather conditions can be treacherous.
"That's why leading tyre manufacturers recommend that drivers change their tyres at 3mm of tread depth to maintain optimum performance. It's very worrying that so many drivers let their tread depth drop so low and leave it to the MOT to check - after all that could be up to a year away."