I've driven back and forth across this country of ours quite a few times, and the one thing I've noticed is the "70" seems to be the magic number. That's the speed the majority of drivers feel comfortable driving at in regards to economy, safety, and getting there in a reasonable amount of time.

I'm a member of the "+9" club. I drive at 9mph over the posted limit with the reasoning that the cops won't stop you until +10 over. I am capable of and would feel comfortable at much higher speeds, but hey, the law's the law.

Others see cars as a necessary evil and will only drive as fast as their nerves, eyesight, or POS vehicle will handle. For some the limit is merely a suggestion to other people.

Then there's everybody else. Whether the limit is 65, 70, or 75, they always seem to end up at 70. An interesting psychological phenomenon I'm sure.

I find the same effect going through highway construction areas....no matter what the posted limit is, 40, 50, 60, the vast majority feel that 50 is just about right.

Thing that make me go "hmmm."