[Twirrim]

Someone did this a couple of years ago for a major thoroughfare near where I lived. They marked it as one way for a key stretch, and traffic ended up being re-routed down much smaller roads to avoid it. It caused all sorts of chaos, both due to the increased traffic on roads not made for it, and in the long queues that formed where the traffic then rejoined the thoroughfare.

It took google at least the best part of a month to fix it (at least, it was around a month from when I submitted the correction, no idea if others beat me to it)