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 t, x/ y3 N( Q2 B- H请问u-turn到底是不是合法的？
谢谢！

EightBelow

U-turns
, D# G/ H7 y* s' n. y6 J• 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
+ ^7 m1 z/ t3 x" ?  o0 mcrest 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:
• On a roadway between intersections.
% ~4 o1 `: v7 C7 q' }• Where a sign prohibits making a U-turn.
! @7 I; B! m- r' t# ]2 D4 G• 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。