Hunh?

There is a sign near here that says, "This turning circle will be converted into a round-about." It says this on (at least) two approaches to the turning circle, and appears to have a (standard for around here) French translation on the sign as well. Looks suitably official.

My first reaction was a big hunh... did I read that right. Driving back through in the other direction, yup, the sign is on the other side, too. I did read it right. Now, to me, that sounds like somebody posting a sign saying that "this road is going to be turned into a street". Well, as far as meaning goes -- I always saw the two as being synonyms for each other -- just slightly different dialects, with round about being more of a British phrase.

I'm still not entirely sure what they mean by the sign -- though I have a guess. For those of you who might be local, it is on the turning circle on Prince of Wales drive as it goes through the Experimental Farm.

Anyone else care to guess what this odd locution might actually mean?