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
2 c' L; j4 \4 Z/ p& ~• Do not make a U-turn unless you can do it safely and without interfering
5 z8 N1 Y( l5 zwith other traffic.
" e* M+ ^5 }! ?% U: d• Outside urban areas U-turns are not permitted on a curve or near the
( L, j8 B; a; l, O$ K( ^0 `' \1 bcrest of a hill where the driver of another vehicle cannot see your vehicle.
7 R1 g# A4 {' S: E% ]2 xU-turns are not permitted in urban areas in the following situations:
• On a roadway between intersections.
• 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。