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？
( |0 k7 H( K, H! j% c# _( P8 f$ m谢谢！

EightBelow

U-turns
• Do not make a U-turn unless you can do it safely and without interfering
6 A/ g9 \( d5 |/ fwith other traffic.
• Outside urban areas U-turns are not permitted on a curve or near the
8 l8 {0 V: H# {5 O, A" T, d; d, ycrest 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:
' W0 }8 I  K" x) V7 q$ m• On a roadway between intersections.
4 G4 p4 V4 X' \5 E" ~• Where a sign prohibits making a U-turn.
• At an intersection controlled by a traffic-control signal (traffic lights).
$ E  L4 W* ^3 i& x) [• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。