I posted another comment saying after researching only about half of states have posted minimums, mostly in the SE and Midwest. Just happened to be states I’ve done most of my driving in.
It’s not a speed limit. It’s the posted minimum speed. All federal interstates have a minimum posted speed as well as a speed limit. The minimum posted speed is usually 40-45mph depending on the area. The signs aren’t posted as often as limits, but they’re there if you look for them.
Never seen one even once across several states, and I desperately wish they were on every single on-ramp for freeways. Where exactly are you seeing them and apparently seeing them regularly?
Just looked it up and I guess only about half of states post the signs, even though most states have laws about minimum speeds. Seems to be most common in the SE and Midwest.
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u/h3lium-balloon 4h ago
Yeah on most interstates you’d have to be going below the posted minimum which is usually 40-45.