32 CFR §935.135

1. (a)Each person making a right turn in a motor vehicle shall make the approach and turn as close as practicable to the right-hand curb or road edge.
2. (b)Each person making a left turn in a motor vehicle shall make the approach and turn immediately to the right of the center of the road, except that on multi-lane roads of one-way traffic flow he may make the turn only from the left lane.
3. (c)No person may make a U-turn in a motor vehicle if he cannot be seen by the driver of any approaching vehicle within a distance of 500 feet.
4. (d)No person may place a vehicle in motion from a stopped position, or change from or merge into a lane of traffic, until he can safely make that movement.