The tread is the grooved outer layer of your tyre that is in direct contact with the road. The rubber compound is designed to grip the road, resist general wear and tear and cope with high temperatures generated by friction.
Sufficient tread is vital to keep you safe in all conditions. New tyres come with at least 7mm of tread. The legal tread limit is 1.6mm – anything below can incur a fine of up to £2,500 and 3 points for each illegal tyre. Recent research is calling for the legal limit to be raised to 3mm.
In an emergency, the risks are many times greater if tread depth is close to the legal limit. Braking distances are significantly increased as a tyre becomes more worn. The level of tread becomes imperative in the wet, where worn tyres contribute to 1 in 10 accidents in wet conditions*.
*AA Motoring Trust