It uses other information too. It wouldn’t go over 45 or so unless it’s clearly a freeway with a divider and other cars were going that fast. And there is proba

It uses other information too. It wouldn’t go over 45 or so unless it’s clearly a freeway with a divider and other cars were going that fast. And there is probably something that uses last known speed, and it remembers speeds it has seen before. But the updates do other things too, like help it understand new kinds of signs or to improve handling of weird situations.