Here I have a question: What is a “median”? I haven’t found much about this in a web search. It’s not documented in the wiki… But according to Taginfo it seems to be used 10k times.
So I can’t say why an area is being “enforced” here…

I reject that. Because the point is that a traffic calming measure is marked accordingly on the highway way. That’s what traffic_calming=* is for.