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？
* T  ?; v3 U: d; F1 y' r谢谢！

EightBelow

U-turns
! }0 l/ s, {0 u, M• Do not make a U-turn unless you can do it safely and without interfering
+ ~/ _, u* h- L6 {7 qwith other traffic.
• Outside urban areas U-turns are not permitted on a curve or near the
- G: c$ b9 h. t5 s6 y! zcrest 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:
7 f; M) R! t) {$ A• On a roadway between intersections.
4 k  r' A4 w5 `" w# m- J9 Y- @• Where a sign prohibits making a U-turn.
• 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。