[Cowboy89]

Originally Posted by Bring_Back_Shantz

Of course roads are designed to be safer than the posted speed (and you could likely drive a lot more than 10-15 over and still be "Safe"). It's called a safety factor and it's applied to anything that an engineer touches. Hell, by law elevators have to have a safety factor of something like at least 7.5 (that means when the elevator says it's safe for 10 people, the actual theoretical limit is 75 people).
That being said, the limits aren't random, and safety factors are there for several reasons:
1) People will speed
2) Not all cars handle the same way
3) Conditions change
So using that as an excuse to speed is stupid, because like any design, there are a lot of assumptions, and safety factors are there because assumptions can be wrong.

As for my position on speeding I'll say this:

When I drive my truck I usually do 10-15 kph over the speed limit, or generally with the flow of traffic.
When I'm on my bike, I'll pretty much cruise on the highway at 140kph.
Do I try to justify speeding by saying it's safer, or by saying that the guy going below the limit is more dangerous? No, because ultimately, both arguements are either incorrect or irrelvant. I speed because I'm impatient, or late, or just want to go fast. I know it's more dangerous, and I take that risk (and I suppose I impose that risk on others), but I don't try to justify it because I know there is no reasonable explination.

Great post!