Currently there are some limitations to navigation while in offline mode. Whilst some are understandable, not being able to see real-time closures, for instance, the biggest problem with offline mode as it stands just now is the cached roads don't seem to respect the segment data that may restrict travel along them.

As a member of the community has found (https://www.waze.com/forum/viewtopic.php?p=2324443#p2324443) when navigating offline, even 24/7 restrictions in place on the map do not get respected and the user gets directed through them.
This could cause many issues for the users involved which would not have came up with an active data connection.

I would suggest having this data saved internally in the app as many other parts of map data must be would make the routing more reliable and trustworthy when the user has an intermittent data connection.
This data is already present in a similar way to turn restrictions which currently do work as expected so the potential is there.