I seem to recall that when I was young, the speed limit here was 80 MPH, It was lowered during the fuel crisis of the middle seventies and early eighties. A 1983 Cadillac Eldorado has a V8 which was installed to shut down to 4 cylinders unless the extra power is absolutely necessary. The other option that year was diesel. Both were to conserve fuel. I believe that the government saw a way to control the speed limit, to perhaps save lives and fuel, by controlling state's funding of road improvements, by withholding federal money if states raised limits. I know the limits are slowly going back up, due to public demand. I think the cars of the seventies with the enormous weight and engine design were the biggest part of fuel waste. I love SUV's but they are the fuel glugging modern day seventies waste mobiles-regardless of speed. I would like to see a study of the fuel consumption of well built driving machines of today, to show what fuel consumption at higher speeds is like. I would think that distance traveled versus usage would be better than at slower speeds.
I feel afraid when I am stuck in a slow moving group on the highway, it feels very unsafe. I also believe that it is illegal to pass on the right. I have noticed that driver's in the fast lane are so eager to get passed a slow car in the fast lane that they change to the right lane to pass very often without any warning, and the slow vehicle is trapped in the fast lane while car after car do the same.
I would like to see a much higher speed limit everywhere, combined with much more strict driving regulations via education.
There is nothing more frightening than an experience I had with another driver recently. I was in the old '79 300SD, in the right lane of three lanes. I was getting off at the next exit. A very new Mercedes merged on to the highway, I moved to the middle lane to let the driver on. The driver of the new Mercedes changed lanes without looking at all, he went from one side all the way over two more lanes to get in the fast lane. He almost took me out of this world, by smashing into the side of me. I braked and changed lanes very quickly to the fast lane(If a car had been in the fast lane that would have been it), fortunately he was going so fast that by the time he was in the fast lane he was 50 yards ahead of me. He never even noticed that he almost killed me. I was very impressed with my old baby. The handling was still perfect.
Forgive me if my information is incorrect.