My stock answer for stuff like this is that, where something that looks like a road is visible in the aerial imagery, then if it isn’t already mapped in Waze as something, it’ll only be a matter of time before it does end up getting mapped. So IMO it’s preferable that it’s mapped in Waze in a manner which causes it to behave as we’d expect it to behave, than to remove it from the map data and then risk having it added in again in a way which causes routing errors…
I’d also query leaving it in place but disconnected, because as the signage indicates there is a legal exemption for vehicles to travel along there. Whether we think anyone would ever use Waze to navigate to a point along it is by the by(way), and even if it’s vanishingly unlikely that anyone might want to route to the byway, it’s less unlikely that someone might drive there for whatever reason and then ask Waze for a new route from a point along it.
So as long as we can leave it mapped in a way that allows people to make use if it when required, without messing up routing for other users, then I’d say leave alone. As several of us have discovered to our cost, leaving map comments explaining why stuff is mapped in a way that looks a bit odd isn’t always going to stop well-intentioned but over-eager editors from fixing stuff, especially if they’re being guided by any of the scripts that like to highlight things which may well be errors, but which aren’t guaranteed to be unless you fully understand the context in which they’re mapped, which in turn may require the editor to have the map comments layer turned on, to then notice that there’s a comment nearby, take the time to read it and understand what it means… Easier to just discourage them from messing in the first place.
One thing I did notice is that the private road heading off to the west has all outwards turns set to red here, which is likely to raise red flags with the aforementioned scripts as well as with the native map problem scanning process that HQ runs in the background. Note that if someone were to come along and fix this problem by enabling all the turns, it’d then allow Waze to route directly from that private segment into the byway private segment, potentially causing the byway to end up being used as a through route from the first private segment in violation of the signed restrictions.
To avoid this, you could either redraw the junction here so that the two private segments don’t form a crossroads (i.e. break the direct route from one PS into the other, which would then prevent use of the second one as part of a through route for drivers already on the first one), or add a short section of normal street type segment to one or both of the private segments (which again would break the direct PS-PS connection whilst still maintaining the crossroads geometry).
Disclaimer: all above advice is my own, other senior editor opinions are available and may differ, may cause staining to lightly coloured fabrics, seek medical advice if swelling remains after use