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？
8 r) s3 H( X* b  @0 q谢谢！

EightBelow

U-turns
• Do not make a U-turn unless you can do it safely and without interfering
( D7 P$ I- |8 xwith other traffic.
6 N6 ~1 e0 G* k• Outside urban areas U-turns are not permitted on a curve or near the
/ K, ~3 h1 Q( P$ e) Mcrest 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:
- m# g1 w& ]. d! A0 ?• On a roadway between intersections.
• Where a sign prohibits making a U-turn.
• At an intersection controlled by a traffic-control signal (traffic lights).
  K7 \  A# h1 a, _/ Y• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。