Actually, this is somewhat related to speeding, and I'd just like to hear your opinion.
On interstate, I always try to go 5-15 mph above limit (this is usually 80), and always try to pass - and the reason for this is not that I'm so agressive, but it is a way to keep me awake.
I'm often driving for several hours, and this is my way to avoid road fatigue and sleepiness. If you go always just a bit faster that the others, then there's always something to watch out for, there's always something to pay attention to - I think if I set the CC at 70 and just blend in the line I'd be asleep in 2-3 hrs.
So I think this is just safer for me. Don't get me wrong, I don't try to go too fast, but I think my car and more importantly my reactions are able to handle speeds under 85-90, so there's always a safety margin.
_sometimes_ I go above 100 for a short while, but always only after making sure that the situation is completely safe (flat/straight/dry road, no slow traffic etc), but on a public road I never feel easy about it - I retain the right to risk my car and life

, but I do not wish to do so with others', let it be an other driver or a deer or a dog or anything else wandering along the road.
Of course, I always wanted to try myself and my car on a track - there I wouldn't have such concerns, and I'd happily speed as fast as I can
Fortunately, I never had the opportunity to tell this story to a cop, but I'm really curious how'd they react to it.
Tivadar