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
9 v4 N2 A' k. r* e% @; N0 ?: {1 Q9 W/ R• Do not make a U-turn unless you can do it safely and without interfering
0 b* W1 C7 g4 x* o; K% B  j( ewith 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.
+ c* n- _) E+ q1 fU-turns are not permitted in urban areas in the following situations:
3 _" Z3 g/ H8 O2 w0 Q; p• On a roadway between intersections.
• Where a sign prohibits making a U-turn.
# Y  |6 n' `0 d3 n* C3 w; r• 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。