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。
1 ]- f- C" C# q% o* A% F& q请问u-turn到底是不是合法的？
谢谢！

EightBelow

U-turns
& J! G7 `% P& s. u0 b• Do not make a U-turn unless you can do it safely and without interfering
% q' r9 z: T8 mwith 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:
1 N  v9 k! |7 }5 z6 r/ T• On a roadway between intersections.
' R, a; I/ y& w• Where a sign prohibits making a U-turn.
, |, v' \) U* G# f• 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。