Right now, when trying to route to a destination on a closed road, it's pretty much like the road no longer exists and Waze will route to the nearest open road.

Sometimes, this means that users will be routed somewhere completely different, like to the middle of a highway, to the other side of a raildroad track into a completely different neighbourhood, etc.

Segments with RTCs on them should be treated as a routable pedestrian path: route the driver to the closest entry point.