Straight median segments 
If the median segment is straight, sum the two angles making up the U-turn:
- The angle between the incoming and median segments (between A and B)
- The angle between the median and outgoing segments (between B and C)
The in and out segments (A and C) are considered parallel if the sum is between 175º and 185º.
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| The short 14m median segment in the above examples satisfies condition #2 for U-turn prevention. |