What should ramp departure angles be? There is currently no hard documented spec. The best I can find is in the "ramp geometry and complexity" section of the global and USA Interchange wiki articles, which instructs to "extend the ramp naturally to create a junction with the road segment, typically at a 10–15° angle". Note that this guidance does not require a 10-15° angle, rather it suggests that the natural byproduct of a "natural" ramp extension will typically be 10-15°.

Why bring this up now? An update requestor took issue with a ramp fix of mine yesterday. I'd left the ramp departure angle at 7° -- not within the wiki's "typical" range, but only 3° outside it, and definitely a "natural" departure angle from the freeway and very common -- and was told the angle should be "bumped up" because the app will fail to make such a slight departure angle available for closure.

This brought up the following questions:

1. If editors should apply un-natural (?) ramp departure angles to compensate for an issue in the app, why isn't it in the wiki?

2. If our wiki is wrong, what is the most correct (un-natural?) departure angle for the purpose of clarifying the app closure screen? 20°? 30°? 40°? Reductio ad absurdum, one could use a 90° angle micro-dogleg and then an instruction override to preserve the "exit" command I'm guessing nobody wants that! But it does offer maximum separability of turn arrows on the closure screen.

3. Should the editing community modify (hack?) ramp exits everywhere to work around this shortcoming in the app, or should we ensure that Waze understands the problem and then wait (and wait, and wait, and wait...) for them to improve the app's closure system (which I believe is already understood to be buggy in other ways and in need of attention)?