>>Remember speed limits are set at the 85% of the median speed, capping out at 70. (or unlimited in daylight time if in Montana)<<
Nope. That ended about four years ago. I drive to eastern South Dakota from Seattle every spring. I used to maintain 115 MPH for hundreds of miles. It was a pretty fast trip. The speed limit is now 75 and enforced.
You'd be surprised what a good bumper sticker can do;
KEEP HONKING-
I'M RELOADING