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？
6 N! h4 w; P7 e谢谢！

EightBelow

U-turns
& x1 I3 A  t( D! Y2 ~• Do not make a U-turn unless you can do it safely and without interfering
3 u8 s1 }" ?$ s' O- L  twith other traffic.
3 K5 D" ]( v7 A+ B• Outside urban areas U-turns are not permitted on a curve or near the
, F; c# [  W' H5 U) Pcrest of a hill where the driver of another vehicle cannot see your vehicle.
: J  A% Q0 N* u2 }4 BU-turns are not permitted in urban areas in the following situations:
9 J6 ]2 B) ]5 [4 L1 M, V• On a roadway between intersections.
• Where a sign prohibits making a U-turn.
& U: D$ p/ f1 o• At an intersection controlled by a traffic-control signal (traffic lights).
0 X' e+ J) K! y! L8 r* f# Y• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。