@lyndaw and @dispatcher35:
These navigations issue pop up because the maps are still incomplete... In that respect, that app is working right, it's just being fed the wrong information!
One of the BEST things about Waze is the ability for the end user to edit the maps!
I'd bet, if you go the Live Map / Update Map section of the Waze website and check out the areas where it was telling you to drive over a median, you'll see some some sort of problem, that you can fix! It's got to be the coolest thing going! Well, that and driving through an area you fixed and having it work right and saying "I did that!" Love it!!!
I will warn you though, map editing is HIGHLY addictive! Have fun!