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。
3 s% Q6 k. _5 |5 F4 t# A; q7 K请问u-turn到底是不是合法的？
谢谢！

EightBelow

U-turns
$ x3 B7 v# [! t0 S9 O• Do not make a U-turn unless you can do it safely and without interfering
% b% U; N- A9 Z( Dwith 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:
! T* y3 Q# c5 K% m' |• On a roadway between intersections.
• Where a sign prohibits making a U-turn.
4 f8 [0 F0 }; i5 Z• At an intersection controlled by a traffic-control signal (traffic lights).
& a+ }& N9 t1 c  U• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。