We had bad traffic a while ago on 395 south, due to road construction. A whole bunch of cars turned off at a random intersection to take what appeared to be an unpaved frontage road. We stayed on the highway because we had our dog with us and it was over 100 degrees. We couldn't afford to have any problems on an unpaved road. The joke was on them. As we crawled along, we eventually saw another line of stopped traffic - on that frontage road. Then we saw cars turning around. I never knew what the reason was. It must have been miserable for all of them.
I used to run both google maps and Waze. Waze was the app that would frequently offer up the weird routes. Eventually I just uninstalled their app. It wasn't worth it to drive through residential streets to avoid 5 min of freeway traffic.