Thank you for taking the time and responding in detail - it really helps a lot. Much appreciated!

Hi, 

The segment in your first link, along with a couple of neighboring ones, has been downlocked for the speed limit updates.  We can adjust the speed limits on Tank Farm when it reopens and Orcutt closes for the next stage of roundabout construction. We hope you'll still be around to readjust these once things go to the new normal, after the roundabout opens. 
 
The broad answer to your question about the "artificial" road closure is that this is virtually never done.

When we find, through careful examination, that Waze is unduly sending unwarranted amounts of traffic through somewhere it shouldn't, we usually look for other methods of discouraging Waze from routing through, before we would institute such a false closure, because there are typically undesirable side effects to dropping Road Closures in willy-nilly,

As it currently stands, Waze does not prefer Spanish Oaks as a way of getting around the Tank Farm closure for anything except routes originating in the immediate vicinity of the neighborhood. It's just too "slow", so there would be no (or extremely minimal) practical benefit to such a closure. See, for example, Waze Live Map routing here. I have entered a persistent Road Construction alert for the location so that users approaching the area will receive an Alert in the app. 

Thanks for your post, please feel free to ask any further questions

Tony