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。
4 h( `' a. {, B7 O) r请问u-turn到底是不是合法的？
/ t& I1 f, P+ b( J谢谢！

EightBelow

U-turns
) j4 _/ W8 m9 V/ C/ x1 }• Do not make a U-turn unless you can do it safely and without interfering
with other traffic.
• Outside urban areas U-turns are not permitted on a curve or near the
- b0 x+ b) w$ L5 _crest of a hill where the driver of another vehicle cannot see your vehicle.
6 P. C  A$ j5 \2 }U-turns are not permitted in urban areas in the following situations:
: N7 d: j, B$ w4 k! I; l• On a roadway between intersections.
' q  _, A- k" X' T• Where a sign prohibits making a U-turn.
• 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。