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。
6 {/ L8 c  X; @+ A2 q9 b5 s请问u-turn到底是不是合法的？
谢谢！

EightBelow

U-turns
/ {, s" L4 ^; i) G+ o• 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
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:
) K- ?) E8 `2 Y. L2 q• On a roadway between intersections.
7 u5 p) S7 j" Z0 b7 M- Q8 P" \, Q• Where a sign prohibits making a U-turn.
, d4 f$ J8 B6 Y( n- [3 _; R" Y• 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。