Overview
- National Highways republished TRIP campaign guidance on June 26, 2026, showing how to use a 20p coin in a tyre groove to check the legal minimum tread of 1.6 mm.
- Driving with tread below 1.6 mm is illegal and can trigger fines of up to £2,500 and three penalty points per tyre, with court action and up to £10,000 in total fines possible if all four tyres are illegal.
- The RAC and AA advise multi-point checks around each tyre and sidewall inspections for cracks or bulges, and they recommend replacing tyres sooner than the 1.6 mm legal cutoff—consider replacement around 3 mm.
- Motoring groups warn hot weather increases tyre blowout risk because air expands inside tyres, so drivers should check tread and tyre condition more often during the current heatwave.
- If a crash happens on illegal or damaged tyres insurers may refuse claims, leaving drivers to cover repair and liability costs, so simple monthly checks or a tread gauge can protect safety and finances.