As far as I can tell, the current configuration of toll/no toll should work just fine for toll-free routing, unless someone can find an example that does not work.  It is a bit "ugly" that someone going south on 183A Toll Road is still driving on a toll=yes way when they paid their last toll - that's the only issue I see here, but since one is already paying tolls, that stretch where is effectively free is not really that big a deal.

This is my take on it as it is now.  If there's an example where it's not routing properly due to tolls, please make an example and we can fix it.