Talk:Junctions

junction=hookturn

I suggest to add form junction=hookturn for intersections only in Melbourne, Australia. Example image:

Jermboy27, 22 June 2012 (UTC)

A "hookturn" is not a property of the whole junction, but of specific lanes. This was already suggested during the proposal of the lanes-extension and it was agreed that a value should be added to the key turn=*. The discussion on the talk page of the turn key got a little stuck, but the only issue left open was a good name for it. Maybe you could revive the discussion there and provide some good ideas. --Imagic 11:18, 26 June 2012 (BST)

Junctions where a road changes name

If a road changes its name at a junction with another road, navigation software has no way of knowing whether to say "turn here" or just let the driver carry on. I.e. the osm data just indicates three ways coming together, it has no indication that one of the ways is just a continuation of one of the others with a different name. Is there any way to tag the junction so this is taken into account? Spookypeanut (talk) 15:05, 25 August 2018 (UTC)

Trying to understand the question: Is that the naming problem I described on the main page in section "Dual carriageway intersections", or a different one? Or are you talking about single carriageways? --Polarbear w (talk) 17:08, 25 August 2018 (UTC)

The issue is sort-of similar, but relating to single carriageway roads. Let me try and draw it in text...

A---1---o---2---B
        |
        3
        |
        C

Travelling from A to B along roads 1 and 2, there is no apparent change of roads, it just changes name. However, I can't find a way for the OSM data to reflect that, so navigation software will assume it's a left turn (depending on the actual geometry, obviously).

Is there a way? Spookypeanut (talk) 21:46, 25 August 2018 (UTC)

Ok I understand you now, but I do not see a problem. Nav software always evaluates the angle of the roads, so from A to C it sees 90 deg and announces 'turn right'. From A to B it sees 0 deg, so (depending on the settings) announce nothing, or say 'follow the road into B'. Most nav software evaluates the angles in between, so it can announce a slight turn, a regular or a sharp turn. --Polarbear w (talk) 14:47, 26 August 2018 (UTC)

But imagine if the main road goes from A to C, and happens to change name at o where a side road comes off: it would be confusing for Nav software to say "turn right", since the driver should just follow the road round. It feels like there should be a way to say "this road is a continuation of this other road" in osm tags/relations. Spookypeanut (talk) 15:03, 26 August 2018 (UTC)

Well I use such nav systems, and yes for A->C they say turn right into C-road, and I do that, and happily arrive in C.--Polarbear w (talk) 15:42, 26 August 2018 (UTC)

Fair enough, I'm happy to leave the issue at that. But just to be clear, there is the potential for confusion if a right-turn happens just afterwards:

A---1---o---2---B
        |
D---4---·
        |
        3
        |
        C

I used OSM Nav software a few weeks ago for the first time, and this did cause some confusion. Just something to bear in mind. Spookypeanut (talk) 19:25, 26 August 2018 (UTC)