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.
• Outside urban areas U-turns are not permitted on a curve or near the
4 q: d2 A( J' G3 c* C) i1 b- `- A1 `crest of a hill where the driver of another vehicle cannot see your vehicle.
1 z; f" L- u, O) H3 _9 x& ^U-turns are not permitted in urban areas in the following situations:
% @8 o$ \; j8 q0 `# _• On a roadway between intersections.
6 s$ R9 x; I% V  L' E• Where a sign prohibits making a U-turn.
# H, H3 b' [9 R6 \1 F. ?# n• At an intersection controlled by a traffic-control signal (traffic lights).
& z6 R, Z/ I& D% q: I) s+ Q4 x• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。