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