有关u-turn

小胡同

最近查google map for directions, 经常会看到需要u-turn。印象之中好像在主路上不可以，不管是否有不可u-turn的牌子。平常也看到有人在红绿灯处做u-turn。
& P& q' p* D* c* C& B; R请问u-turn到底是不是合法的？
谢谢！

EightBelow

U-turns
' m/ U- ~, |* Q" e4 ~• Do not make a U-turn unless you can do it safely and without interfering
* R( A7 F( z; ~with other traffic.
4 N" Y' a( O- d4 q" b• Outside urban areas U-turns are not permitted on a curve or near the
crest of a hill where the driver of another vehicle cannot see your vehicle.
/ c! {( D- K" Z. VU-turns are not permitted in urban areas in the following situations:
5 @; n* X% N/ E& ^  |• On a roadway between intersections.
• Where a sign prohibits making a U-turn.
• At an intersection controlled by a traffic-control signal (traffic lights).
: P$ w' V' V8 V  _• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。