When the Kansas Turnpike was new, it had the highest legal speed limit in the US...80MPH. Still, many treated that like they do most speed limits and assumed they could exceed that by 10-15%....I think there is this 'wisdom' that the law NEVER means exactly what it says.

Folks did learn better on the Kansas Turnpike when they found out that the toll tickets were stamped with entry time, and when they left the toll road, it was easy to calculate elapsed time and issue tickets based on the average speed over the limit!

So...what happened? Guys who loved speed would drive 90-100, stop for lunch, then finish their trip. There is some innate wiring in some, (fueled by testosterone, I guess) that says that the posted speed is the minimum