If all the cars are always mapping and collecting data will maps ever be out of date?
Then think of what percentage of the time they're right.
But hey, that's not a realistic danger in the city, right? Well, look up the sinkhole named "Steve" that opened up in the middle of an Oakland, CA freeway.
Then there's Highway 1, which is known for landslides. Not to mention that little incident with the Bay Bridge back in '89...