Tyre tread helps the car grip the surface it is travelling on. Tyre tread comes in all sorts of styles and patterns suited to the environment and terrain they a meant for. A bit like shoes eg; football boots, ballet pumps, wellies, walking boots, they are made to give you the best support and protection for their use.
In wet weather, tyres and their tread are designed help evacuate water from the point of contact between the tyre and the road to ensure that the grip is as effective it can be. If the tread on your tyres is worn and under the legal limit, it could well be that in wet weather conditions your car could aquaplane, a dangerous situation where you lose all control over the car as the contact with the roads surface is broken by the water that cannot escape due to insufficient tread depth.
In wet conditions a car with good tread depth can fill a bucket in just 7 seconds, THAT’S 514 BUCKETS AN HOUR!!
Watch this demonstration of how a car with poor tread copes in the wet.