Worn tyres can be deadly: according to industry body TyreSafe, nearly a thousand car accidents a year in the UK are caused by illegal, defective or under-inflated tyres. And while, by law, the minimum tread depth is 1.6mm, it’s all too common to see tyres well below this level – despite the risk to the driver and other road users.
When we go to fit new tyres, we measure the tread on all of the tyres on our customers’ vehicles, which gives us plenty of information on the state of the nation’s wheels. Using data from over 213,000 tyre measurements by TyresOnTheDrive professionals, we decided to find out where the country’s worst culprits for illegal tyres can be found.
This heatmap shows the postcodes with the greatest concentrations of tyres below 1.6mm in red. Newport, Swansea and Hereford were the biggest offenders, with 19.8%, 19.7% and 17.8%, respectively, of the tyres examined by our staff falling below the legal minimum.
In fact, Wales and the West of England seem to fare decidedly worse than the East. The best-performing postcode was Colchester, where just 0.8% of the tyres we replaced were illegal, followed by London SE and Bromley at 0.9% each. In general, London came out well – of the 90 postcode areas surveyed, six of the capital’s main postal districts appeared in the best 20.
But how much difference does tyre tread really make? In 2003 and 2004, the Motor Industry Research Association did tests on four different cars to reveal that, when braking at a speed of 50mph on a wet surface, a vehicle with tyres on the legal tread depth limit of 1.6mm takes on average 39.5 metres to come to a complete stop – that’s a full 13.6 metres more than new tyres with 8mm of tread.
Those 13.6 metres could easily be the difference between a narrow miss, and a much more serious accident. And that’s not to mention the fact that drivers face three penalty points on their license and a fine of up to £2,500 per tyre for driving on tyres below the legal limit.
If you’re concerned about the state of your tyres, use the 20p test – put a 20p coin into the central tread groove of each tyre on your car in a couple of places, and if the inner ridge of the coin’s rim can be seen above the tread, your tyre’s under the limit. Get it changed as soon as possible or risk a fine, points on your license – and possibly worse.