tread on a road tire, is like a duck on a bicycle....siping makes sense on vehicle tires where you can exceed the magic hydroplane speed of 10.6 times the square root of the air pressure in PSI. At a 100 psi in you tire, you don't have to worry until 106 mph, when riding in a heavy rain. Now you know one reason Boeing 747 tires run such high pressure, the other is to increase the load carrying capability for a relatively small tire.

Tread on bicycle road tires is just for looks....