Many states have laws against obstructing traffic. Most of them don't mention a specific minimum speed so enforcement is largely at the discretion of law enforcement officers. Personally I would like to see strict enforcement of those laws with tickets given out to anyone who intentionally impedes the flow of traffic.
Obstructing traffic is very different than “driving more slowly than the person behind you wants”. Obstructing means blocking, not making them wait 30 seconds for a good chance to go around.
If you are moving a large item that is fragile, are you allowed to go 35mph in a 45mph zone to reduce the risk of damaging the fragile item? Or is that illegal too? Or what if one of your passengers gets car sick easily?
In fact, there are some winding mountain roads in California where the speed limit is 55, but if you go that fast, you’re suicidal because there are no guard rails and very sharp turns. Occasionally, someone mildly suicidal will come up behind you. Is it illegal to drive 15mph in that 55 zone?
Safety is prioritized above speed, suggesting otherwise is unhinged and antisocial.
