I don’t know about speed signs but here in Illinois every body of water that a road passes over there is a sign with the name of that body of water.......I’m not talking about lakes or major rivers but every drainage ditch or small creek it passes over. ..
I’m sure it is important for people to know that they just passed over “Little Lamarsh creek” that is 2 feet wide and dry 90% of the year...and half mile down the road is the next one and so on...../s
I enjoy reading those signs.