How has this "standard" come to be? I have seen new depths of 6/32 (DOT legal racing), 10/32 (performance tires), 11/32 (standard), 12/32 and 13/32 (off road and a/t), 14/32(? - Mud). Unless they are really "specialty" tires, most seem to come with 11/32's tread depth when new. Who came up with this number and why? I have my own thoughts on the matter but would like to hear from those in the know. I understand the hydroplane resistance as well as snow or off road traction but what is preventing us from having a new tire at 15/32 with interconnecting ribs and such to reduce squirm and improve handling?