This thread isn’t being very helpful one way or the other, because we’re all talking about different snippets of information about driving.

The law, in certain states, is to go the speed of traffic if you’re in the left lane. In other states, it’s to keep the left lane clear unless to pass.

The rules of the road in general is to follow signage and drive at the speed which feels safe based on the conditions of the road.

In some places, the conditions of the road can be good enough that it’s not a major concern to go even five miles over. In other places, driving the speed limit could actually be dangerous since that’s too fast depending on the time of day, the season, or due to wear on the road itself.