I have created a turn feature class to prohibit certain multi-part U turns. It is working just as I'd expect when I solve for routes. The problem is: we are using Navteq data as our base for creating the network dataset and Navteq provides quarterly data updates. I would like to be able to import the turn feature class to the updated data (understanding that it wil only be applicable where Navteq features remain the same -- which is of course the majority of features). I've tested importing my turn feature class into an older Navteq version and built the network dataset. The problem is: even though the majority of road features have not changed, my turn restrictions are not being honored as they were earlier. I'm looking for a way to retain my turn restrictions when I update the (mostly unchanged) base data.