[meyer]

"A lower speed limit means a lower death and injury rate."

That was an argument when the speed limit was raised from 55 to today's limits. The reports of highway carnage were grossly exaggerated - the death toll didn't rise, and IIRC, it fell. Perhaps people are less fatigued after driving 7-8 hours than they are driving 10 hours while covering the same distance.

[Binghamton_native]

And to add to your excellent point, for those driving long distances, perhaps across country, obeying the 55 mph limit will probably mean an extra day on the road. So now where are the dollar savings? In addition, what are the consequences for long distance trucking if the trucks are also forced to a lower speed?

If fuel is saved at a lower speed for autos, is fuel also saved if planes fly slower? If so, perhaps Congress should also edict a top speed for jet travel. /sarc.