A U-turn in driving refers to performing a 180 degree rotation in order to reverse your direction. It is called a "U-turn" because the maneuver looks like the letter U. In some areas, the maneuver is illegal, while in others it is treated as a more ordinary left turn, merely extended. In still other areas lanes are occasionally marked "U-Turn only".
Sometimes, on a divided highway, special U-turn ramps exist to allow traffic to make a U-turn.
