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。
' W9 j0 b) R' e' S5 S& s请问u-turn到底是不是合法的？
& W0 v$ M1 g( R# U+ e0 d谢谢！

EightBelow

U-turns
2 n* g  W% y5 o4 h• Do not make a U-turn unless you can do it safely and without interfering
with 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.
U-turns are not permitted in urban areas in the following situations:
• On a roadway between intersections.
, r* j; B: ?  B• Where a sign prohibits making a U-turn.
• At an intersection controlled by a traffic-control signal (traffic lights).
  n4 Q4 a4 W4 O! [0 J' r# \+ M; z6 }• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。