[talk-au] iD and turn restrictions (Was:Re: Talk-au Digest, Vol 178, Issue 44)

[Andrew Davidson]

On 30/4/22 00:45, Anthony Panozzo wrote:

> This account is either a bot account or someone that thinks they know 
> more than they actually do, every single time anybody does a routing 
> correction this account comes along and “fixes” it based on “knowledge” 

Some terminology before we start. To be valid a turn restriction 
relation needs to have:

1. A way with the role "from"
2. A way with the role "to"
3. One or more "via" s that can be either a node or one or more ways
4. The members must connect in a way that you can travel

When I say "broken" I mean that one of the rules is broken and when I 
say "knowledge" I mean I know what a valid turn restriction should be.

> from the notes, let me just say I looked over some of the edit this 
> account does and it breaks the routing for the most part, Changeset: 
> 120344373 | OpenStreetMap 

This changeset deleted this turn restriction:

https://osm.mapki.com/history/relation/13905961

which you added in changeset 118257827 and then broke in 118293106 (it 
only had a node via member). When I reviewed this one I decided to 
delete it because it would only duplicate this turn restriction:

https://osm.mapki.com/history/relation/14044389

which you added in changeset 119769921, if I fixed it.

> <https://www.openstreetmap.org/changeset/120344373> and Changeset: 
> 120198383 | OpenStreetMap 

This intersection had 15 broken turn restriction relation in it:

https://osm.mapki.com/history/relation/13477255
https://osm.mapki.com/history/relation/13477256
https://osm.mapki.com/history/relation/13477257
https://osm.mapki.com/history/relation/13477258
https://osm.mapki.com/history/relation/13477260
https://osm.mapki.com/history/relation/13477261
https://osm.mapki.com/history/relation/13477263
https://osm.mapki.com/history/relation/13477268
https://osm.mapki.com/history/relation/13477269
https://osm.mapki.com/history/relation/13557714
https://osm.mapki.com/history/relation/13761157
https://osm.mapki.com/history/relation/13761161
https://osm.mapki.com/history/relation/13761169
https://osm.mapki.com/history/relation/13761170
https://osm.mapki.com/history/relation/13991446

You broke 14 and added one new broken relation (13991446). While I was 
deleting these I noticed that the intersection had some sort of 
cross-your-heart thing going on with added ways for turn lanes, so I 
simplified it to a standard traffic light box intersection:

https://www.openstreetmap.org/#map=19/-34.76387/138.59277

You can turn right from each arm which means we don't have to have any 
no-right turns. There are 4 no-left turns because each approach has a 
slip lane. Since it's SA and at traffic lights then there are four no 
u-turns to cover that. This is exactly the same routing information that 
was there before, but now in a simpler easier to maintain format.

> <https://www.openstreetmap.org/changeset/120198383#map=17/-34.76452/138.59301> 
> are two examples of this account breaking routing, ive been wasting my 
> time spending hours and hours fixing routing just for this shitty bot to 
> come along and fuck it all up over and over again, I would like to ask 
> DWG to take a real close look at this account and see if it can be 
> banned from any further edits under the bot edit policy or straight out 
> vandalism!

I am not a bot. Just a mapper with overpass, the JOSM validator, the 
to-do plugin, and many hours of puzzling over the question of what a 
broken turn restriction relation was supposed to be doing.

A couple of years ago I spent quite a bit of time fixing all the turn 
restrictions around AU, but I have to keep coming back every couple of 
months, as 100-200 newly broken ones get created every month. Mostly 
because iD will quietly break existing turn restrictions or let you 
create invalid ones and then upload them to OSM. I used to put changeset 
comments on the ones that had broken them until a user asked me how they 
could stop doing it and I discovered that there isn't a way to do that 
in iD.

My fixes should not be changing any routing outcomes as they are almost 
all deleting turn restrictions that iD didn't clean up after a mapper 
reconfigured an intersection. None of the examples you have pointed to 
have changed the routing outcomes as I check to make sure I understand 
what someone was trying to map before I fix it.