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。
; W5 a- u+ S6 O请问u-turn到底是不是合法的？
谢谢！

EightBelow

U-turns
• Do not make a U-turn unless you can do it safely and without interfering
( G& O; M; S- W' ?& Q+ S, ywith other traffic.
7 C5 b/ O! |% \4 k1 V  f• 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.
: l5 J7 I- ]" y/ r5 V1 w6 p8 U( X0 ]U-turns are not permitted in urban areas in the following situations:
• On a roadway between intersections.
0 p5 j5 V; ^# F7 h! z9 a• Where a sign prohibits making a U-turn.
$ q. S! b8 B9 s6 g3 [! u• At an intersection controlled by a traffic-control signal (traffic lights).
• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。