Talk:Key:abutters

abutters no longer favoured?

I'm quite surprised to find this still documented as thing worth using. I know abutters tags were used a lot when I first started OSM, and they were rendered on Tiles@home (different coloured strips by the roads) but I thought they were no longer favoured these days -- Harry Wood (talk) 23:34, 7 April 2016 (UTC)

The absence of obtrusive "this tag is deprecated" banners is indeed curious. Perhaps this key has become so utterly forgotten that people don't even remember to change the wiki entry...? --Tordanik 17:48, 13 April 2016 (UTC)

From who\where do you get 'official' permission to give such a banner. Seems the three of us are in agreement. I don't know of any formal process, but if there is, I'd want to go through that rather than just tag it up that way myself errantly. JeopardyTempest (talk) 21:51, 7 May 2016 (UTC)

Hm actually, in most states in the US, the default speed limit differs depending on whether a given road is in a residence district or a business district. source:maxspeed=US:urban doesn't work there.

So, abutters=* is or would be actually the perfect tag for this because it is also verifiable on-site. See Default speed limits for which states in the US make this distinction --Westnordost (talk) 22:25, 31 July 2020 (UTC)

I'd rather not encourage use of a tag that pretty much duplicates landuse information. Surely, something like maxspeed:type=US:residential (or US-CA:residential if necessary) can be invented that would suit the use case just fine and won't spread outside the areas where it's actually relevant. It would also make it clear that the relevant definition is the one from traffic law. With abutters, there might be other potential use cases suggesting different definitions. --Tordanik 19:49, 14 August 2020 (UTC)

Well, it only duplicates landuse information to a certain degree because there is no landuse=mixed but there is abutters=mixed - you know, for example these typical mostly-shopping-streets in suburbs where most ground stories are rented by shops and stories above are apartments, the landuse would just be residential. But anyway, I see the following problems with maxspeed:type=US-CA:business:

1. Using the maxspeed:type=* scheme to describe these areas means that any mapper that attempts to map maxspeed must internalize the complete set of maxspeed zones and how they are defined in the local traffic law valid in the state he is in currently before he can start mapping. This is quite an audacious requirement for mapping so naturally few would actually observe this which results in rule of thumb mapping anyway. Or actually, the real situation in the US is that maxspeed:type=* is not really used at all that much.

2. In each state in the US, the legislation is a bit different. One state makes this distinction (residential, business, rural), another does not (urban, rural), others still make further distinctions (suburban residential, urban residential, etc.). So it must be US-XX:suburban_residential (ISO 3166-2) even though currently exclusively the ISO 3166-1 alpha-2 standard is used for maxspeed:type=*. I reckon this is probably not a big problem, but:

3. The US citizens I talked to about this (on slack US) did not tire to tell me about that in their state, the law allows individual muncipalities to override the law, which means that not even in one US state, one can guarantee that there are always the same legal road categories. So, what, US-CA:Los_Angeles_residential then? The more one goes into detail, the more convoluted this scheme becomes.

4. So to summarize points 1-3, these legal categories are volatile, even more so than in Europe. (Example of new road categories popping up in Europe/DACH: Begegnungszone, Fahrradstraße.) But at the same time, to map correctly, all possible road categories need to be defined beforehand. (Not even for Germany we have a complete mapping of legal categories to equivalents in the maxspeed:type=* scheme.) This is problematic.

5. The maxspeed:type=* tag does not record ground truth, but a legal category derived from some ground truth, why not just immediately map the ground truth? Why do we tag the contents/interpretation of a law book onto each and every street on OSM? It seems really unnecessarily complicated and makes it less easy to verify.

6. maxspeed:type=* is an information exclusively meant for implicit speed limits, so it will only be set if no explicit speed limit is defined. The kind of legal zone is however (depending on the legislation) important for other things as well, not only speed limits. In school zones in some states, I read that higher fines apply for speeding, just an example, I am not an expert on US traffic law, I am sure there is more. But in Germany for example, parking is not allowed on main roads outside built-up areas, so parking:lane:both=* would implicitly be "no" for rural main roads.

So for these reasons, I think abutters=* or any other similar tag that records the actual ground thruth like lit=* (in UK, lit roads count as "urban" in traffic law), bicycle_road=* or living_street=* (both are signed as such, so it's also ground truth) are vastly superior to any tags that record a mapping of a legal category. The legal category may change, or the definition thereof may change, or new legal subcategories may be created, all the while the ground truth stays the same. Further, maxspeed:type=* just defines the legal category for speed limits, but what about the legal categories for parking, for fines, for priority rules or whatever else there may be. We could invent even more tags for that (f.e. parking:lanes:zone=DE:rural), or we acknowledge that tagging legal categories as such is problematic and should be avoided if there are alternatives that record instead the ground truth.

Sorry, that comment was longer than expected, but this was going around in my mind for a very long time. It is also mostly a case against maxspeed:type=* and not so much for abutters=*, only insofar as that abutters=* is a ground-truth and locally verifiable tag --Westnordost (talk) 23:42, 14 August 2020 (UTC)

Ok, legislation is complicated and potentially different in every municipality. Does that mean that abutters=* will also have different definitions and values in every municipality? If not, I don't see how it can be used to derive legal rules. If I set a road to "mixed" according to a global OSM definition, or according to my gut feeling, but it should be "residential" according to local law (maybe they don't have a mixed category there at all, maybe they draw the line differently), that's not going to produce correct speed limits?

I agree that mapping ground truth is preferable over mapping the legal effects thereof. So the reason this problem exists, imo, is that abutters is not really ground truth. "Here's a house", "here's a playground" and "here's an office building" are ground truth facts. Abstracting from those physical objects to an abutters value for a road (or a landuse value) is a subjective judgement call for which there could be many possible criteria. If you rely on me knowing and using a specific set of criteria (e.g. those relevant for traffic law), I'd rather you made that obvious. --Tordanik 10:24, 15 August 2020 (UTC)

Well, ideally abutters=* isn't oriented at any particular definition in legislation but just by the rule of thumb definition as you see it here in the wiki because we won't get anything more precise anyway from the average mapper. As long as there are no signs ("Welcome to business district X"), a recorded information by rule of thumb will be about as precise as the rule of thumb estimation of a driver who has to decide whether something is a business or residence district in absence of any signs and thus may drive 25 mph or 30 mph for example. So that's a precision that's good enough.

In other words, in absence of signs denoting a legal category, it is not possible to have a 1:1 reflection of the definition in legislation in OSM anyway and then it is better to not delude ourselves by using tags that suggest that (US-XX:suburban_residential) but tags where it is clear that a (fuzzy) ground truth is recorded and thus a translation into a legal category may not be absolutely precise.

That being said, I recognize and agree that abutters=* is quite fuzzy, but so is landuse=*. So it must be made clear that it is to be understood as something with no clear definition (unless there are signs). Those legal categories by the way are in many legislations in the single states by the way equally fuzzily defined, something like "consists mostly of buildings where people do business" and something like that. (The initially linked wiki page has all the links to the actual legislations, you can look it up if you are interested) --Westnordost (talk)