Yes. In some (most?) states, the leftmost lane on a motorway above 65MPH is supposed to be used for passing only. What makes highways dangerous are large speed

Yes. In some (most?) states, the leftmost lane on a motorway above 65MPH is supposed to be used for passing only. What makes highways dangerous are large speed gradients and this is an issue caused by drivers both on the high end and the low end of speed. Hence why most highways have a minimum advertised speed. The issue is that no one respects the speed limits anymore which often expands the gradient and makes the highway less safe. Left lane or not, you shouldn’t exceed the speed limit.