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
* i8 g1 a/ P% A• Do not make a U-turn unless you can do it safely and without interfering
: C* i4 I( i3 L4 [with other traffic.
* |% u: l4 m. h: [* H• 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.
U-turns are not permitted in urban areas in the following situations:
( A& o' E9 B8 D' c. N• On a roadway between intersections.
) S2 z) L! h+ n) M* q• Where a sign prohibits making a U-turn.
• At an intersection controlled by a traffic-control signal (traffic lights).
  ]- W% h3 G( y. z9 ^  w• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。