Link roads between different highways types

As i see on this , why is it not made ‘simple and clear’ ? :roll_eyes:
I can understand the ‘logic’ of ‘From → To’ , that is clear and simple … for example ;
From primary to service/unclassified/residential/tertiary/secondary/primary = primary_link → logic and simple … but …
right beneath that, there is ;
From primary To trunk = trunk_link, and also From primary To motorway = motorway_link … :roll_eyes:
confusing, and not ‘simple’ … :roll_eyes:
Why not (in those cases) also the From-link(primary) ??

I ask this, because that is why maybe this ‘mistake’ of 2 different translations for ‘trunk’ may have occurred ?

I’m not sure I understand the confusion. Always tag the link with the highest class road. If a primary and a motorway connect, use motorway_link. If a trunk and a tertiary connect, use trunk_link.

This does lead to micromapping where for example people start motorway_link from the point where the motorway sign is and have a small stub of primary/secondary/whatever. IMHO this is unnecessary (and even though we do not tag for the renderer, I find this extremely unappealing on the map).

OK, clear and logic … thanks for reply.
EDIT : i added your sentence (Always tag the link with the highest class road.) for better understanding … :wink:

seems like someone is not agreeing with your explanation → https://wiki.openstreetmap.org/w/index.php?title=Link_roads_between_different_highways_types&diff=next&oldid=1686884

i am not a ‘mailing-list’-guy, so, if someone else would ‘discuss’ this ? :roll_eyes:

I don’t know but many vehicles are prohibited to drive on motorway (including motorway links), such as bicicles, light motorcycles (scooters) and tractors. Usually the motorway sign implies that the road is forbidden for those vehicles, starting at the sign. Mapping a longer or shorter motorway_link than where the sign could make routing applications incorrect for those vehicles. Ok, for 99% of the cases this won’t make any difference and nobody would care, but we can’t rule out that this could be a potential issue.

As for tagging I’ve always done actually the opposite of what is explained on that wiki page, that is, use “links” of the “smallest” type, except with motorways/trunks link because of the rule I stated above where this excludes some types of vehicles.

This is just because it makes the most sense to me. A primary road connecting to a tertiary road will have a lot of traffic in the primary axis, and medium traffic on the tertiary traffic. This means the traffic on the links will also be medium, and therefore “tertiary link”. Another reason I do this is exactly what Maarten said - even though we do not map for the render, it looks more appealing on the map to have the primary road straight without fingers going in all directions.

However if there’s widespread agreement that’s wrong, and that it should be corrected to what is explained in that wiki page, that is having it with “primary_link” and changing brutally to “tertiary” when the link connects to the tertiary road, then I’d definitely change it to make everything standard.

Why should someone go on a _link, just to end up at the highway= where it is forbidden to go by this vehicle? It doesn’t make any sense to me.

A _link road should only lead to the highway it links to. If there are (sensible, not crossings where you are not allowed to go like bicycle crossings) junctions before the main road, I would not tag it as _link.