User:Voludu2/TIO Streets not meeting at right angles View history

(→‎Streets meeting at less than 46 degrees: Clarified from "correct audible instruction" to "turn". Tried to simplify instructions for streets meeting < 20)
(→‎Streets meeting at less than 46 degrees: Overhauled language after discussion in forum)
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==== Streets meeting at less than 46 degrees  ====
==== Streets meeting at less than 46 degrees  ====
[[File:Wme slight right overriden.png|left]]When streets meet at less than 46&deg; the default turn instruction may not end up being true to life. The instruction may be "stay to the left/right" when drivers would consider it a turn, or "exit left/right" when the driver would consider it a "stay" or "turn". If a junction's angle of <46° corresponds to the natural path of the driver’s path approaching the junction, then a TIO for turn left/right should be used. If the angle is adjusted to >46° and < 170° then the Waze app will produce a "turn" instruction by default.
[[File:Wme slight right overriden.png|left]]If drivers reaching a junction tend to slow and/or stop at an angle less than 46° to the cross road, but a turn left or right instruction is still warranted, a TIO may be used to force a turn instruction. Angles greater than 46° will issue turn instructions automatically and should not be overridden.
There is no need to search for and adjust intersections currently using doglegs or microdoglegs (the previous best-practice approach to correcting turn instructions). They can be replaced if the intersection needs to be edited for some other reason. Any Intersection using a "stub to nowhere" or "fake alternate name" to control turn instructions can be corrected to reflect reality and use Turn Instruction Override to control the instruction.


If the intersection has a departure angle of < 20°, it may be best to adjust this to something between 20° and 25° for two reasons: 1) to make it easier to select the correct arrow in the Waze app when reporting road closures; 2) to make it easier for senior editors working mobile to select the correct segment for uplock or downlock
Before Waze introduced override capability, editors forced turn instructions at such intersections by adding "dogleg" geometry nodes to ensure junction angles between 46° and 170° exclusive.  When concerned about display, editors added doglegs at such fine scale as to be nearly invisible; these are called "micro-doglegs".  Doglegs and micro-doglegs continue to work properly and there is no present need to replace them with overrides.
 
Note that doglegs remain a correct and useful technique.  They are completely appropriate when they reflect the typical path of drivers as they slow and stop for a turn. Even if drivers tend to approach at very sharp angles, doglegs may be used to widen the junction angle to at least 20° whether or not a TIO is used.  This makes it easier for drivers to identify the turn for closure via the app, as well as for editors to select the segment when using limited mobile tools (typically to drop or raise locks by request).
 
Other pre-override instruction-forcing methods, especially short "segment to nowhere" stubs and deliberately incorrect alternate names, are no longer appropriate.  They continue to work, however, and should be updated only with care.

Revision as of 15:29, 12 October 2017

Streets meeting at less than 46 degrees

If drivers reaching a junction tend to slow and/or stop at an angle less than 46° to the cross road, but a turn left or right instruction is still warranted, a TIO may be used to force a turn instruction. Angles greater than 46° will issue turn instructions automatically and should not be overridden.

Before Waze introduced override capability, editors forced turn instructions at such intersections by adding "dogleg" geometry nodes to ensure junction angles between 46° and 170° exclusive. When concerned about display, editors added doglegs at such fine scale as to be nearly invisible; these are called "micro-doglegs". Doglegs and micro-doglegs continue to work properly and there is no present need to replace them with overrides.

Note that doglegs remain a correct and useful technique. They are completely appropriate when they reflect the typical path of drivers as they slow and stop for a turn. Even if drivers tend to approach at very sharp angles, doglegs may be used to widen the junction angle to at least 20° whether or not a TIO is used. This makes it easier for drivers to identify the turn for closure via the app, as well as for editors to select the segment when using limited mobile tools (typically to drop or raise locks by request).

Other pre-override instruction-forcing methods, especially short "segment to nowhere" stubs and deliberately incorrect alternate names, are no longer appropriate. They continue to work, however, and should be updated only with care.