Translations:Road Aspects/8/en History

Double left and double right


The Waze routing algorithm prevents double-left or double-right turns by using an extremely large U-turn penalty when these conditions are met:

  • Three segments: The U-turn is a reversal of driving direction through three segments: an incoming segment (A), a single median segment (B) and an outgoing segment (C).
  • Short median: The median segment (B) is shorter than or equal to 15 meters.
  • In/out parallelism: The in and out segments (A and C) are within ±5° of parallel to each other. If the median segment isn't straight calculate the degrees as if an imaginary straight segment was connectining the A and C segments.
  • Not all the A, B and C segments are Street.
  • The two nodes interconnecting A, B and C are not in a Junction Box.

Example / see picture: Driving from left to right on the top street (A) with destination towards the east requires a reversal of driving direction. When the median segment B (red arrow) is 15 meters or less the app will navigate over the lower street towards the east. Only if this median segment is 16 meters or more the app will navigate over the bigger road in the middle (C).

See also the global page on Routing penalties/Controlling U-turn penalties