Maybe so, but I would like to point out that most places that have a 55 mph or greater limit are limited access highways without intersections, driveways, school cross walks, etc. It’s not often you have to come to a complete stop. 16 mph over the limit on a limited access highway is no where near as bad as doing it in a 25 mph zone, which is typically in a residential area.
So, let’s just forget about the volume of traffic on those limited access highways, and the potential for road hazards (such as a ladder that falls off of a pickup truck). That 16 mph increase does become extremely crucial when there are road hazards (and since no one can predict when something will happen, then if you choose to drive over the posted speed limit the onus is on you if something happens).