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
8 L5 z+ Z" ]" S8 fwith other traffic.
0 Y7 d' \% ?" q0 d• Outside urban areas U-turns are not permitted on a curve or near the
. ?6 z5 r& Y  ~  y+ b& wcrest 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:
+ _! F9 |5 |; Z7 B) J9 p" [• On a roadway between intersections.
$ Z5 b3 y8 J( T% H3 f& }• Where a sign prohibits making a U-turn.
% }. V- h& z6 P' K4 v• 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。