Moved U-turn distance to template
==Best practices for different types of crossings==
Crossings can be classified according to the number of single and split(double) roads involved in the crossing. For each of these there exist solutions to prevent U-turns.
Why prevent U-turns?
* We do not want Waze to suggest illegal routing. Ever.
rarely legal, but Waze will suggest one on each and every occasion where it thinks it is appropriate. (In Germany U-turns are allowed in most cases, except they are permitted by sign.)
* Ad-hoc routing is better when U-turns are not possible.
This cannot be remedied completely in editing. A roundabout always allows U-turns. Going around the block can be fast enough to make another try at the original route.
*'''U-turns can be prevented by reducing the length of the segment crossing the median to less than
15m and leaving this segment unnamed.'''
*Simple 3-Way-Crossing (SSS)