[OSM-talk] razed railways and other things that don't exist today

[stevea]

Some historical perspective on a project like OSM, its growth, the social aspects of "what that means and does to tagging" over time might be helpful.  The dates and numbers I'm about to offer as examples are wholly illustrative (and indicate not arithmetic, but geometric growth, a very powerful force) and are no way based in reality because I've "done the research on the actual numbers," because I haven't.  I'm simply making a point or two.

Let's say early in OSM's history, oh, 2005 or so, there were 10 mappers worldwide who began the first tendrils of rail mapping, and that by 2006 that grew to 50.  People in sizes like that can talk to each other and agree on things to a 100% level of agreement, or pretty close to 100%.  This is because the "problem set" has a small enough size that its "solution set" can be hashed out in a few emails, not many kilobytes of wiki, and heads nod in almost perfect unison among a relatively small group of people.  If you are "in the club," it's easy, and even quite fun!

By 2007 (and, for example, the USA's TIGER Import of hundreds of thousands of km of rail) there are 500 active, enthusiastic rail mappers in OSM, and lots of work to do, and it feels like maybe "1% of the problem" (of mapping all of Earth's rail accurately) has barely had its surface scratched.  On the social dimension, this remains manageable, especially as things fragment in to different countries, and hundreds of people still might only be a couple, a few, or maybe at most a dozen, even in a very complex rail area (like Germany or greater Europe):  "localization of the solution space" really does help a lot.  This remains doable, but people eye the future and imagine public transport and better renderers, and so allow a timeline of a few years for these things to develop.  It remains relatively easy, especially if you "remain local / regional," and "others (clever ones, busy ones, more-curious ones...) "think globally."  OSM is fine.

Fast forward to 2010-11 and now there are many thousands of rail mappers and things like PTv2 move from "good ideas" to "coming on strong," OpenRailwayMap gets rolling, major differences in how rail all over the world show that the problem is large, maybe quite difficult if people are honest, and yet it remains manageable as the tools get better and the numbers, while growing and at least medium-sized, are not totally overwhelming.

I can go on with real life examples (from this time period of 2014-16-18-20-22, and personally, as I've given SOTM talks, one on rail...) and had a fair bit to do and say about "rail growth in OSM" in my own country (USA), I've seen this growth — geometric growth — and how it has had to cope with rail over the one-to-two centuries this transport technology has been around (including ORM and OHM as examples of how OSM "maps" it, both logically and literally).  There are now hundreds of thousands of rail mappers in OSM, in over a hundred countries.  Think of the "social dimensions" of not only "that" but "how that has grown and continues to grow."  The amount of fragmentation of understanding (especially given humans' many languages and both the limitations of using English and the "Balkanization" of isolated language communities) has now become quite large...maybe "huge" by some people's estimation.  Logically mapping how we have, do and will put "razed" (demolished...all the other flavors) of "doesn't (completely) exist today" rail into tagging schemes that we all agree upon, especially given that many don't have OSM's now-decades-long historical perspective of "how things (like tagging) have grown up w.r.t. rail in our project" are now "difficult," but remain explainable and doable.  I believe we are up to the task, but it is complex, the geometric growth compounds this, so do the relatively long (in software-, data-project world sense) timescales, and especially (in a project like OSM), the social dimensions (of consensus, multilingualism and so on).  We (all of us in OSM who might map rail and other things "that don't exist today") are still "in the club," but it is less easy to talk amongst ourselves about why we "do this" (but "not that").

And, I'm simply talking about "razed railways" (and a bit more).  It's big and complex, and doesn't "shoehorn" (get forcefully or uncomfortably crammed) very well into a small box.

Now, please understand there are many, many other topics in OSM which are not completely unlike "razed railways" (and why they are an "odd duck" and don't seem to categorize well, or need a lot of explaining, or both).

One of my points?  Often, the history of how we got here and oddities of why go a long way to explain.  But the natural human desire to understand quickly and not necessarily digest all of that makes for quizzical or difficult understandings.

Thank you for reading.