[Talk-ca] ON prefix on Ontario highways

[Andrew MacKinnon]

I've noticed that User:Zachary77F has been adding the prefix "ON" to a
lot of provincial highways in Ontario. I am not sure whether this
makes sense (looks kind of weird on the default Mapnik renderer)
though this convention seems to be used in the US for state highways.
Should I keep provincial highways tagged this way or should they be
changed back to the way they were?