AFAIK it's not illegal but I do recall a driver complaining either here or in uk.t that they had been stopped and fined for doing this, the reason given was driving without due care and attention I think.
There are places where a similar manouever makes a lot of sense, at a T-junction wishing to turn right, where there is heavy traffic and a roundabout to the left. It's nicer for all concerned to turn left got to the roundabout and do a 360 and come back the other way. It actually causes fewer holdups. Sadly at one place where I work the thick locals dont' get the point and there will always be at least one hbuttled looking mother in a car indicating right, blocking anyone from turning left and not having a chance in hell of ever being able to pull out. Or at least not until the rush hour is over.
Yes that happens often and it's just bloody dangerous. Also I suspect illegal.
Seen it, don't udnerstand it it blocks the junction and gives them very little advantage. I frequently pbutt the person who did the junction hop a few miles after the incident has cleared.
-- "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."
-- Benjamin Franklin, 1759
