Counting of service exits on service roundabouts

[oxidase]

OSM has 13150 ways ["highway"="service"]["junction"="roundabout"]; in which service exits will be suppressed and guidance instructions will be "take the 1st exit". Most of the service roundabouts are located in large parking areas like airports or hospitals and guidance can be confusing in these areas.

For http://map.project-osrm.org/?z=18&center=40.479392%2C-3.477795&loc=40.478358%2C-3.479485&loc=40.480883%2C-3.477607&hl=en&alt=0

the third instruction must be "take the 2bd exit"

In #4073 commit 588563c changed the exits counting, but not related to the PR.

[emiltin]

with the current work on roundabouts, keep in mind that roundabout exit instructions are kind of broken for cyclists and pedestrians, eg. #2533. you can of course use serviceroads, and also push against oneways.

here's an example of a roundabout with highway=path on both the roundabout and all exists:
https://www.openstreetmap.org/way/119182066

and a roundabout with a cycleway exit:
https://www.openstreetmap.org/way/8131031

[emiltin]

here's a roundabout with one residential exit, two service roads, and a cycleway:
https://www.openstreetmap.org/way/22999368

https://www.google.dk/maps/@55.7395107,12.4945035,3a,75y,31.51h,75.59t/data=!3m7!1e1!3m5!1sjcniSTl7sapWU_o0FI8gmw!2e0!6s%2F%2Fgeo2.ggpht.com%2Fcbk%3Fpanoid%3DjcniSTl7sapWU_o0FI8gmw%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D304.90176%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656

[oxidase]

@emiltin thanks for pointing to the issue for non-car profiles! i will check in scope of this issue, but ignoring service roads on normal roundabouts atm is expected behavior for car profiles. Here http://map.project-osrm.org/?z=19&center=55.739516%2C12.494368&loc=55.739479%2C12.494186&loc=55.739648%2C12.494454&hl=en&alt=0 "the 1st exit" is correct.

Maybe a special handling for cyclists and pedestrians is needed, but i would open an issue after a check.

[emiltin]

yes my point is that the current behaviour does not work for foot and bike routing.
even for cars i'm not sure i think the current behaviour makes sense, e.g. in the example no matter what exit you take, you get 'take 1st exit':
http://map.project-osrm.org/?z=19&center=55.739332%2C12.494454&loc=55.739479%2C12.494186&loc=55.739174%2C12.494679&hl=en&alt=0