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
with other traffic.
, A4 K5 H9 Q# [' F: }% z8 A• 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.
& l! k5 b5 N& M3 w2 I( I% U& vU-turns are not permitted in urban areas in the following situations:
• On a roadway between intersections.
; X. J4 V/ a+ g$ [2 V0 [: t) o• Where a sign prohibits making a U-turn.
• At an intersection controlled by a traffic-control signal (traffic lights).
2 D% |& `7 N& O3 j: ?/ i2 i• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。