After more testing this junction is giving a turn right at 43.69°PesachZ wrote:I did some more testing with a tweaked version of the JAI script showing 2 decimal places. The angle described above giving a KEEP instruction ["closer to 43° while JAI still displaying 44°"] was actually 43.68°.PesachZ wrote:After adjusting the geometry if the right branch to be ever so slightly smaller, closer to 43° while JAI still displaying 44°, the fork now gives keep left/right instructions for both sides. This lend credence to the theory that there are different calculations being employed by the JAI script and by the server. Therefore an angle of exactly 44.5° will be treated by the server as 45°, and displayed by JAI as 44° (as described in my original post on this subject).PesachZ wrote:This ramp split junction was brought to my attention. It is ramp to ramp, 22 degrees left, and 44 degrees right. It is giving a "Turn right" for the right branch, and nothing for the left branch (treating it as Best Continuation). All connecting segments have different names.
I'm wondering if one of these might be the cause, I'm leaning toward the first option. These are my own theories.
A) There is discrepancy between the precise angle displayed by the Junction Angle script, and the angle the server uses to determine instructions. I believe after looking around a bit (HT:dbraughlr in WME chat) that this is a function of the script and server employing different methods determining the turn angle and therefore rounding in opposite directions. So a 44.5 degree turn in JAI script shown as 44 degreesmay be seen by the router as 45 degrees.Code: Select all
JAI 180-(135.5 rounded)136=44
To support this theory there are junctions in which all the angles sum to 359 degrees or 361 degrees, showing that the rounding is not precise.[/i]Code: Select all
SERVER starting from 0+(44.5 rounded)45=45
B) The threshold for keep vs. turn has become more narrow, and is now less than 45.5 degrees.
If anyone can take a look, and/or has any information on this, please chime in.
EDIT: Added theory to A)
Adjusted geometry of ramp to be a smaller angle but still displaying as 45 degrees so theoretically if it was 44.5 deg, it should now be less, and work properly. Will test after a tile update to prove theory A. 5/25/14 23:38 UTC
The easy solution here is when editing a junction avoid saying a turn angle of 44°, and to be safe stick to either 0-43°, or 45-90° in either direction.
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I then tested at exactly 44.00° and got a TURN instruction without editing anything else in the junction.
I am now testing at 43.96° to determine if the actual exact threshold used by the server is not 44.5° as previously believed but 44°.
I will hopefully have an answer to this after the next time update. It can then be confirmed by testing on other junctions. I am now leading towards theory B and don't believe this to be a rounding issue. I believe the issue is caused by the fact that any angle between 43.5 and 44.5 well display in JAI as 44, making that angle carry two possible instructions. If this is true we should update the geometry wiki to avoid using 44° angles, as it would be impossible to know what instruction they will provide without a tweaked JAI script.
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and this one is stay right at 43.59°.
We can safely say the threshold is as far as I can tell somewhere between 43.59° and 43.69°. at these angles its hard to narrow further, but the average editor will not have access to decimal points anyway.
I think we can edit the wiki to say
- 45° or higher = turn
- 43° and lower = stay
- 44° is a gray area which usually will be turn, but can be stay in very few cases (the first 1/5th°).
Re: [Page Update] How Waze determines turn/keep/exit maneuve