These situations absolutely occur. Something like this happened to me in Alexandria, VA, trying to cross the Woodrow Wilson bridge into MD. I-495 was slow across the bridge. Waze re-directed me off the interstate into residential side streets, along with thousands of other travelers. The side-streets were every bit as jammed as the highway. It took me 3 hours to disentangle myself from that mess. Was it faster than staying on the highway? No idea, but 3 hours to cover 5 miles is terrible - the app should have just said "You're fucked, go home and try again tomorrow." instead of constantly telling me "oh hey, try this other side street, it'll save you 45 minutes!"