Interactive junction instruction algorithm

This will be a clickable interactive guide to determining 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.

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.

The interactive algorithm

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

YES

NO => No Instruction

Is the destination part of a Roundabout?

YES, see section on Roundabout instructions

NO

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

YES

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?

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 => Keep/Stay 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

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

The instruction in a right hand traffic country will be Exit right.

In a left hand traffic country this instruction does not exist, and will instead give a Keep/Stay_Right instruction. A junction with this exact setup but a left angle turn would give an Exit Left instruction in a left hand traffic country.

Turn Left

Keep/Stay Left

Exit Left

The instruction in a left hand traffic country will be Exit left.

In a right hand traffic country this instruction does not exist, and will instead give a Keep/Stay_Left instruction. A junction with this exact setup but a right angle turn would give an Exit Right instruction in a right hand traffic country.