Interactive junction instruction algorithm Discussion View history

Revision as of 20:24, 2 June 2014 by PesachZ (talk | contribs)

This is a clickable interactive guide to determine what instruction, if any, will be given at the junction between any 2 segments.

There will eventually be encyclopedia style illustrations for the various configurations to visually describe the setup. This will formatted as a sequence flow through, to cover (hopefully) all variations.

Introduction

Understanding how and which instructions are provided requires first understanding a few concepts.

  • This page is discussing the instruction which will be provided by the Waze server (or not provided) when travelling from one segment, through a junction, and onto a second segment.
  • How Best Continuations work. Any time the destination segment is the Best Continuation there will not be an instruction provided.

While the illustrations displayed by each question may not represent every possible variation, they do represent the difference between the two options in that question. Please choose the most appropriate answer.

Definitions

  • The segment you are on before going through the junction, in other words the segment you are coming from will be referred to as the origin, and corresponds to s-in in the the algorithm text provided by Waze staff.
  • The segment you will be on after the junction, in other words the segment you are going to will be referred to as the destination, and corresponds to s-out in the the algorithm text provided by Waze staff.
  • Any segments other the destination which leave the junction at an angle less than 44° will be referred to as other branches, and corresponds to s-N, or s-1,2,3,4... in the the algorithm text provided by Waze staff.
  • When the beginning portion two segments are directly on top of each other, meaning they both leave the junction at the exact same angle as each other, they will be referred to as an overlapping segment.
  • Any road typed in Waze as a Freeway, Major Highway, or Minor Highway, will be referred to in this page as a highway.


Directions

To use this interactive flowchart;

  • Start with the first question in The Interactive Algorithm.
  • Click on the appropriate answer which best matches your situation. A new question will jump to the top of the screen
  • Continue answering the questions until an instruction is displayed at the top of the screen.
  • This is the instruction that the Waze server should give when transversing this junction between the two segments you described as the origin and the destination.


The interactive algorithm

Other than the origin and the destination, are there any other segments connected to this junction?


continue junction turn junction At Grade Connector

YES


dead end cul-de-sac dead end

NO => No Instruction



Are the origin or the destination part of a Roundabout?


Round about street round about MH mH round about ramps

YES, see section on Roundabout instructions


intersection bowtie

NO



Is the turn angle from the origin to the destination between 44.5° and 135°?


YES


to AGC image


NO, the turn angle is less 44.5°

Turns with angles greater than 135° will follow the same instruction path as 44.5°-135°, but the Waze routing server will penalize this turn, and avoid routing through it.



Which direction is the turn?


Left => Turn Left


Right => Turn Right



Are there any other branches with unrestricted turns from the origin?


YES


NO => No Instruction



Is there more than one (1) other branch?


YES


NO



Are the two branches (the destination and the other branch) overlapping?


YES => No Instruction


NO



Is the name of the origin and the destination identical?


{{| border="1" cellpadding="10" |- ! scope="col" bgcolor="lawngreen" | YES |}


NO



Are the origin and the destination the same road type?


YES


NO



Are both the name AND the road type of any of the other branches identical to the origin?


YES


NO => No Instruction



Is there any other branch to the left of this branch?


YES


NO



Is this an overlapping segment, is it overlapped by any other branch?


YES


NO<



Are the segments in a right hand traffic country (such as the USA)?


YES => Keep/Stay Left


NO



Is the origin a highway?


YES


NO



Is the destination a highway?


YES => Keep/Stay Left


NO => Exit Left



Is the origin a ramp?


YES


NO => Keep/Stay Left



Is the destination a highway, or a ramp?


YES => Keep/Stay Left


NO => Exit Left<



Is the name of any of the other branches identical to the origin?


YES


NO => No Instruction<



Are the origin and the destination the same road type?


YES


NO



Is the name of any of the other branches identical to the origin?


YES


NO



Is the road type of any of the other branches identical to the origin?


YES


NO => No Instruction



Are the segments in a left hand traffic country (like the UK)?


YES => Keep/Stay Right


NO



Is the origin a highway?


YES


NO



Is the destination a highway?


YES => Keep/Stay Right


NO => Exit Right



Is the origin a ramp?

YES


NO => Keep/Stay Right<



Is the destination a highway, or a ramp?


YES => Keep/Stay Right


NO => Exit Right

The instructions

No Instruction

There will be No instruction given passing through this junction. This can be caused by several factors including

  • Best Continuation
  • The instruction would be Continue Straight (this doesn't yet exist in Waze)

  • Certain cases with an overlapping segment





Turn Right





Keep/Stay Right





Exit Right

NOTE:
  • In a left hand traffic country this instruction does not exist, and will instead give a Keep/Stay_Right instruction.
  • You will only get an Exit instruction on a turn angle less than 45°, because it is assumed no true exit would have a turn sharper than 45°.





Turn Left





Keep/Stay Left





Exit Left

NOTE:
  • In a right hand traffic country this instruction does not exist, and will instead give a Keep/Stay_Left instruction.
  • You will only get an Exit instruction on a turn angle less than 45°, because it is assumed no true exit would have a turn sharper than 45°.






















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