...how do YOU know that the conditions are suitable for driving at 160Kph?

I would guess that if I were on a properly maintained limited-access road with multiple lanes in each direction and guardrails or a center median separating me from oncoming traffic and as far ahead of me as I could see there were no other cars traveling my direction... I would certainly have no difficulties driving my Porsche (930 Turbo Carrera) at 200 KM/Hour and feeling perfectly safe in the process.

tanstaafl.