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。
( f" Q4 B) e7 Y4 B: m1 ]& i1 D$ c请问u-turn到底是不是合法的？
2 z2 V+ t7 A$ B9 b9 @2 Z( y谢谢！

EightBelow

U-turns
$ |2 M2 v5 E/ \& j5 T5 O$ \9 A$ x• Do not make a U-turn unless you can do it safely and without interfering
with other traffic.
! h& o  o" C* F/ E: J: R( r) Z• Outside urban areas U-turns are not permitted on a curve or near the
' n4 H. k2 I! S) v9 }crest 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 A! t1 K+ E3 e8 \• On a roadway between intersections.
0 R" j9 f1 U8 A* I- Q) g; r4 Z• Where a sign prohibits making a U-turn.
2 J$ a; C, e/ P$ O& H# A• 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。