Should left turns be restricted where a slip lane exists?

Hi,

I tried to add a number of turn restrictions to the map database along Maroondah Highway between roughly Mitcham and Lilydale. They were rejected. I added these restrictions to the left-hand turns where there is a slip lane to do the turn. Obviously, a driver is required to use the slip lane before the intersection, and not turn left at the intersection. See the intersection of Yarra Road and Maroondah Highway, Croydon for an example. A car heading South must use the slip lane (which is present on the map) prior to the intersection. If a car continues into the intersection, they must turn right.

Why were my changes rejected? Should these turn restrictions be included in the Here Map Creator, or is there some policy that I am not aware of?

Thanks,
Map Man