Minimum legal tyre tread depth

fuse:
i am starting my own tyre supply company for lgv and cars i think the tread depth should be minimmum 5 mm acros full width of tyre with no cut anywhere on the tyre .No really i think the laws on tyrers is just fine as it is.i think they are trying to drum up more trade .i do not see anywhere near the amount of blown tyrer s on theroads as there used to be. if brake want to do more on safety get the hours cut to something sensible like the train drivers but with no loss of pay

One of the motoring programmes (Fifth Gear IIRC) did a test where they compared the stopping distance of a car with 1.6 mm tread against one with 3 mm tread, and the difference was quite considerable.

Of course, it would be interesting to know what they did to confirm that all the other conditions were identical (e.g. condition of the brakes, etc…)

Tony1968:
By contrast a bicycle doesn’t need any tread as the high ground pressure (80-100psi) and low speed isn’t enough to lift the tyre off the ground. (OK, it’s not impossible, Schwalbe calculated that a slick would aquaplane at around 200Kph).

I’ve aquaplaned on my bike - mountain bike tyres (about 5 cm wide), tyre pressure about 45-50 psi, and I hit a deep (approx 3-5 cm) puddle stretching across the whole width of the road at about 40 mph. Fortunately, I only wanted to go in a straight line, and the puddle was only about 5 metres long.