→Controlling Turn Instructions: added link back to basics, 0 degree angles, rewording of examples.
Before going further, make sure you understand the mechanics of [[Map_Editing_Quick-start_Guide#Turn_restrictions_.28allowed_turns.29|turn restrictions]] in the Map Editor. If turns are not properly enabled and restricted, you will never get the instructions you desire.
In the Basics section above, we touched on how to ensure a "Turn left/right" instruction would be given over a "Keep left/right" instruction. Details of the mechanics behind this can be found on the [[How_Waze_determines_turn_/_keep_/_exit_maneuvers|How Waze determines turn / keep / exit maneuvers]] page, but a summary is provided in the sections below.
=== Geometry ===
* Approximately '''90''' degree departure angle = '''Turn'''
* Between '''20 and 30''' degree departure angle = '''Keep''' (or Exit for Ramps)
These angles allow us to clearly depict the desired result (turn vs. keep) while staying
within safe margins of the angles the actual algorithms use for decision making. For example, since 45 degrees is a trigger point for the algorithms, a 44.5 degree angle will behave very differently than a 45.5 degree angle.
Similarly, if we have a [[#Y_Intersections|road split at a Y]] and we want to be clear about which is "straight" and which bears off to the side, having one branch at zero degrees and the other branch at 5 degrees isn't
as clear and obvious as if it were zero degrees vs. 20 degrees. Since most of us will not have a protractor handy every time we are editing, it is best to simply avoid situations where exactness would matter.
This knowledge allows us to control how a junction behaves by modifying a single geometry node in most cases. This is often useful for [[At-Grade_Connectors|At-Grade Connectors]] where sometimes we prefer a "Keep right/left" and other times a "Turn right/left" would be more appropriate.