I'm starting to get why IT folks hate users.
The road by our house is currently being torn up and rebuilt to lay a new sewer line consequent to the earthquake. Half the street is blocked off with heavy equipment and big holes.
At the traffic circle to turn down my road, there's a big "No Right Turn" sign. As you enter the street, navigating between a whole pile of road cones that limit entry, there are three signs. The first says "Local Resident Access Only". The second says "No Through Road". The third says "Road Closed".
After the turn for a small cul-de-sac that runs off of Estuary Road, there's a more formidable set of barricades with the sign, again "No Exit", and a narrow gap through the cones to allow access for residents. At the end of my block, there's a set of barricades preventing through traffic from continuing onto the next part of Estuary Road.
I watched one car do a U-Turn at that final barricade every 5 minutes on Saturday. On Sunday, I watched the Number 5 Bus do a U-Turn there too. It wasn't gracefully executed.
I could buy some small number of folks making U-turns there. If you didn't know whether, say, 197 Estuary was on the North or South side of Beatty St, you could err. But one every five minutes? And a bus?
It would be mildly fun to have one person sit at the traffic circle and count the proportion of people approaching the circle with GPS devices on the dashboard and compare it with the proportion of folks making U-turns with GPS. Rather a few folks making U-turns seem to have them, but I don't know the relevant base rate.