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
• Do not make a U-turn unless you can do it safely and without interfering
7 m8 w8 E, \$ {! X0 k: hwith other traffic.
) T) @* S/ l) U7 s3 l1 C  ~• Outside urban areas U-turns are not permitted on a curve or near the
* B% U5 P' ~: n) ecrest of a hill where the driver of another vehicle cannot see your vehicle.
  ~! V& L: w! [% aU-turns are not permitted in urban areas in the following situations:
; c! N+ E5 L1 F' m; S4 q• On a roadway between intersections.
8 x; _6 k, U, Z. g• 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。