I would suggest making up a tag value rather than using just "yes". A new descriptive tag is more useful as a plain "yes", because its sole existence indicates "yes" and the value describes the thing at least a little bit.

However, "2 metal poles on each side of the road and 1 in between with a speed limit sign" kinda sounds like traffic_calming=choked_island ? "Choker" is a narrowing of the road, and the pole in the middle creates an island.