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。
请问u-turn到底是不是合法的？
谢谢！

EightBelow

U-turns
, o  T* `7 \4 p1 A" c2 r• Do not make a U-turn unless you can do it safely and without interfering
+ `1 Q4 e" N  ]8 Vwith other traffic.
• 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.
/ I; s: U0 Y: vU-turns are not permitted in urban areas in the following situations:
% t$ E' o: R0 i! P# J+ q• On a roadway between intersections.
3 u' V8 R- U0 K( H: m* L3 A' k. m  t• Where a sign prohibits making a U-turn.
• 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。