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Zverik's Diary

Recent diary entries

Welcome to OpenStreetMap!

Posted by Zverik on 20 April 2018 in English.

— Yay, new mapper! Welcome to OpenStreetMap!

— I see you are using wrong tags. Please read Map Features and don’t come back until you’re done. I don’t care if it’s too long. Go to Google Map Maker if you’re intimidated.

— I don’t know you. Please go to talk@ mailing list and introduce yourself and reasons for your mapping. Yes, I know you have to sign up using some obscure web page, and then receive unwanted mail for eternity. But rules are rules. Go do it, or leave.

— I see you work for a mapping company. I will be watching you, because you do not care for our map. None of you do. Yes, I am working at such company too, but I care.

— I caught you not tracing from Bing like the rest of us. Please explain your sources and acquire specific permissions for using these. Or better stop.

— I see that among 500 buildings you’ve traced, 20 have been recently demolished. I know that they are still on imagery and in the registry. But it looks like your quality of mapping will never reach mine. Please go away and never come back.

— Hey, I’ve seen more edits from you. I think we’ve discussed it. I don’t care if they are good, I have reverted them. Please do not come back.

— Hi new mapper, welcome to OpenStreetMap!

Turn restrictions are pretty common to OSM, them being the second most popular relation type, after multipolygons. Usually a restriction is a relation with two highway ways, “from” and “to” and a “via” member connecting these. The value of “restriction” tag adds a meaning: which kind of turn is forbidden on this route. For example, “restriction=no_left_turn” (and any other no_* value) forbids going from “from” to “to” way using “via” intermediate objects. Alternatively there are “only_*” values, forbidding any routes from the “from” way except the one leading to “to”.

Usually “via” members are nodes, which makes them redundant for all types of restrictions except “no_u_turn” (which has the same way in “from” and “to” roles). Thus supporting them in a routing libraries has been easy. But — a “via” member can also be a way. For example, on a dual-carriageway, like the one pictured below. Supporting ways for “via” members is hard, but they constitute less than 3% of all restriction relations, so developers have often ignored these.

See full entry

The Subway Validator evolves

Posted by Zverik on 19 March 2018 in English.

First, thank you all for improving the mapping of subway networks all around the world! In just half a year, we made more than 150 networks routable, of 180 total. That is very impressive. Today, OpenStreetMap has more data on subways than any other source, open or proprietary.

Last week, I have made a few improvements to the validator. The major one is a change to how stations are counted. We had an issue of transfer stations: for some cities they were counted once, for other — twice, depending on how they are mapped. This simplified calculating a projected total number of stations (just copy it from wikipedia), but affected mapping.

Now, thanks to disc12, it sums up numbers of stations for each line. This is more predictable and allows for different interchange mapping styles. In the spreadsheet, counts of stations have been mostly updated in form of a formula: =line1+line2+…+lineN. You can clearly see how many stations it expects for each subway line. If you find an error there, add a comment and I’ll update the number.

Having trouble with missing or extra stations? Click on “Y” near the city name, and you’ll get a YAML file with all stations, transfers and lines. What’s new is a number of stations for each line (calculated as a number of unique stations for all its itineraries), along with a list of stations. Comparing it to wikipedia is much easier.

There are some improvements planned still. For example, handling of stations under construction: you cannot add these to routes at the moment, or you’ll get an error. And there is a “nowhere near the tracks” error that is hard to track — I really should do something with it. And the preprocessor calls for a GTFS output.

Thanks for mapping, now let’s finish the last cities and then monitor the world for new subway and light rail stations. If you are an app developer, please consider using the validator output for your app. Contact me if you have any questions.

Subway Routing in Maps.Me

Posted by Zverik on 25 December 2017 in English.

Last week we published the latest version of Maps.Me. It’s got the major version number increase — 8.0. And not for nothing: there is a brand new “Discovery” button, which shows interesting places around you. There are christmas markets on the map — not from OSM though. You can register as a “local guide”, meet new people and show them around your city. Hotels from booking.com can be filtered by price, rating and availability.

But that is not why the release is worth celebrating. The main thing is, we’ve made a metro routing!

Screenshot of an Underground route in London

It won’t be an exaggeration to say that this is the first even public transport routing application that uses solely OpenStreetMap data. Anybody can employ GTFS data, but using OSM is not that easy. All these relations — “route”, “route_master”, “stop_area”, with enourmous tables in the wiki detailing their usage. Utter mess in the data, a result of mapping for a renderer. Very few people understand public transport mapping, so how did we even use it?

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I broke my streak

Posted by Zverik on 19 December 2017 in English.

A few days ago I forgot to spend a minute in an OSM editor. I had almost a month of consecutive edits, level 3 in OSM Streak with almost a hundred points. And then, after a hard day, I forgot about even opening a laptop. Neither an email, nor a telegram notification helped.

Participating three days in a row

The next day I submitted my first changeset in a row. How much did I lose in the game? I had been receiving five points for each changeset (I was too lazy to complete tasks), now I get three, completing the tasks. The fourth level was two months ahead, now… I don’t know, two and a half? 500 points is a long way to go.

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A year of edits with OSM Streak

Posted by Zverik on 3 December 2017 in English.

Hi, I am Ilya and I have been uploading changesets 15 days in a row. Not because I’m so into it or somebody makes me: I’ve made a tool that reminds me to do it. In a year I expect my HDYC activity chart to be completely filled. And you can have the same too.

Introducing OSM Streak: a website that gives you points for submitting changesets each day. You get 1 point for the first changeset, and then you get more: for example, I will receive 4 points for my next changeset tomorrow. And that is not all: it gives you a random task each day, so you don’t stare at the map trying to come up with an idea. For completing a task, you get an extra point. And when you map many days in a row, you gain levels, which open more tasks.

Forgetting to visit a website is expectable, so OSM Streak is also a Telegram bot (find the link on the “Connect” page). With the bot, you can forget about the website: it accepts changesets and sends you tasks every day. Alternatively, you can subscribe to e-mail notifications, which will be sent on 1:00 UTC.

All the tasks and the website and the bot can (and should!) be translated into your language. We have English and Russian, and I would be very grateful for more translations.

Finally, there are 26 tasks at the moment, and you can add more by making a pull request or an issue on github. You can also use the source code as an example for writing a telegram bot, doing migrations with peewee ORM, sending e-mails with python or adding i18n with transifex.

Hi. I’d like to ask you to the Metro Mapping proposal page, read it in full and leave your vote below. The proposal mostly summarises subway and light rail mapping practices and introduces a few useful changes, listed in “What This Affects” section.

You will find many opposing votes there. You might be tempted to read only these comments and skip studying the material. It is simpler, and some of the authors are well-known in the community: they must know what they are talking about, right? And there are 8 screens of text, who would read that?

That is what I don’t like in the current proposal system. It does not matter what the proposal actually contains, how deep an author knows the topic or if the features in questions are already mapped in a suggested way. What a great power you have when the voting starts — strike out weeks of work by writing a few words! You must be a fool not to excercise that power. And who knows what might happen if the proposal is approved? Everybody understands you cannot edit a wiki page after that. You would need to write your own proposal, and it might be rejected, so it is safer to just oppose.

For the first time in OpenStreetMap history I started actually using the data to route users through subways. And found out the tagging is insufficient: there was no sane way to map interchanges, and you could put thousands of members into some relations. For a mapper things also looked bleak: to map a subway properly, you would have to know how underground tracks go, and where underground platforms are located. No wonder that a beta version of a validator showed that the world had like three subway systems mapped good enough, out of nearly two hundred.

See full entry

We all used building:levels and alt_name without giving it a second thought. Why are these keys built that way? Why not levels:building? To me, it looks like there is a rule for building composite keys.

Suffixes

ref is the basic tag for storing a reference number. For a reference number in some third-party table, we add a suffix: ref:third_party. That is because the new tag still contains a reference number. We have all such numbers in ref* keys. The rule of thumb is, the meaning of a value is defined by the basic tag before the suffix. ref:third_party is still a ref, and source:maxspeed is a source.

Sometimes we cannot use suffixes for historical reason. That is the case with name: we use name:en and other suffixes for names in other languages. For that reason, we build composite keys by prepending a content with an underscore: local_name or place_name. These are still names — a reversed order from the semicolon notation.

Of course, an underscore is also used for multi-word keys: public_transport and admin_level.

Namespaces

Then, there are namespaces. The most known is addr: with addr:housenumber and so on. Without a suffix, addr key has no meaning. The same with contact: and turn:. Namespaces are used for marking a group of tags that have the same meaning, have similar value formats and they are usually described on a single wiki page.

Some namespaces are used for tying properties to a part of the object described by the main tag, and for adding more specific properties of it. For example, building:* tags describe attributes of a building, and we also have roof:type and fire_hydrant:type. These words are most often put on the same object as a key or a value, e.g. building=yes or amenity=fire_hydrant, but also can mean a part of a structure denoted by these tags, like how buildings almost always have a roof.

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OpenStreetMap Awards 2017

Posted by Zverik on 28 July 2017 in English.

Did you know that the community voting for the OpenStreetMap Awards is open right now? We have chosen many nominees that did a great job last year, 45 of them! Not as many as the total number of active community members, but still a lot. And nine will receive the award at the Stat of the Map in August.

All nominees will be features in the series of OSM Blog posts: https://blog.openstreetmap.org/tag/awards2017/

Help translate the website and project descriptions to your language: https://www.transifex.com/openstreetmap/osm-awards/dashboard/

The voting closes on 16th of August. Vote now — you can change your choice at any time. Nominees would be glad to hear they are supported by hundreds of voters, so we would need at least a thousand people to vote.

Promote the Awards in your local communities, and if you are nominated, do encourage your subscribers to vote for you :) That is okay, provided you don’t pay for votes or anything like that.

Better Walking Papers

Posted by Zverik on 5 July 2017 in English.

Walking papers from the Tula Mapping Party

I have talked publicly about improvements to walking papers since at least SotM 2013. Made a blog post here in 2014 with some thoughts. But all I’ve seen were new ways to print tiles or atlases. While I admire the Field Papers and MapOSMatic fork improvements over the past years, a good walking paper is more than that.

For a long time I have been using a 28-step process to prepare walking papers for my mapping parties. It involved using Maperitive, Inkscape and some proprietary software. This year I finally got fed up with reanimating that old renderer, which doesn’t work perfectly on Linux, and tried something else. I had always been recommending QGIS for printing maps, and I decided to try it myself. Turned out, making walking papers with it is really simple and straightforward, albeit not without issues.

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The 2016 Board Elections Statistics

Posted by Zverik on 23 January 2017 in English.

The OSMF Board elections happened a month ago, but only now I’ve got my hands on the anonymized ballots. Which means we are getting some statistics.

First, let’s look at numbers. By the 10th of November we had 457 members eligible to vote. That is much lower than the previous year, when we had around 500 eligible members. Still, that’s just a tiny fraction of active OpenStreetMap editors, so the room for improvement is huge. Other numbers have also dropped: 4 candidates instead of 11 in 2015, and 253 voters (55%) instead of 272 (~53%).

It was definitely the fastest and simplest of OSMF elections: with only four candidates, two of whom were running for re-election and other two much less known in the community, 77% of first choices were either Frederik or Kate. That is, Kate got three times as many first votes than the runner-up. I doubt there is a system in which the outcome of the voting would be different.

A chart for mentions and first places for each candidate

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POI Edits by Editor

Posted by Zverik on 29 December 2016 in English.

The editor usage stats wiki page has two useful tables for comparing editors: by number of users and by number of edits. And while MAPS.ME reach is clearly visible in the first one (alas, it hasn’t still surpassed iD in users), the second table has much lower numbers for the mobile editor. Which is reasonable: MAPS.ME does not allow editing geometry, thus a single user can make more edits in a day, than all MAPS.ME users in a month.

I was wondering if we could compare only the type of edits our mobile editor allows, that is, POI edits. And with daily replication diffs, I did:

Created and Modified POIs by Editor, total

This chart shows that while users of iD and JOSM editor create more points of interest than MAPS.ME users, it’s not by a large margin.

I noticed days when 10k or 20k new POIs were uploaded with JOSM, and wondered if the picture would change if we took median values for days of each month. That is, from a sorted array of numbers we would take the middle number. Turns out, not much.

See full entry

100 € for multiple social accounts in OSM

Posted by Zverik on 14 November 2016 in English. Last updated on 7 December 2016.

Last time it went pretty well, so let’s try another long-standing issue. Namely, #1274.

You can register or log in to the OpenStreetMap website using a social account: Facebook, GitHub, Google. The thing is, most of us have many social accounts, but you can only link one to your OSM profile. If you click a wrong button, you will have to either go back or register a new account. You cannot log in to your account using different social buttons.

For me, that is a problem. I would like to not remember which of the buttons I clicked when I tested the social login, and which of these is linked to my main OSM account. For that I would like a social accounts management in the settings page. Alas, I don’t have time and skills to add that, but I have a hope that somebody has. And for that I’m willing to pay a small grant: a hundred euro, like the last time.

The offer stands for two months: the pull request to openstreetmap-website should be submitted until 15th of January and merged until 15th of February. Right after merging I will transfer 100 € to any given credit card or bank account.

Tagged and Untagged Nodes

Posted by Zverik on 18 October 2016 in English.

I’ve just counted some statistics on a planet file from 14th of October. Here it is:

A table with node statistics

This table shows a number of nodes, both tagged and untagged, that are referenced by ways and relations. You can see that nearly 97% of 3.5 billion nodes are untagged, and most of these — 88% — are part of exactly one way or relation. Like, when you trace a building, you add four untagged nodes that are part of that closed way.

98.4% of all nodes are part of something, but only 12% (424 million) have two or more parent objects. This could help with designing a data storage for nodes.

There are equal amount of tagged nodes that are not part of anything, and part of an element. Interesting are these 9 million tagged nodes that are part of two or more ways. The taginfo says there are 2.5 million crossings and 860 thousand traffic signals, so that’s a ⅓ of that.

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Short history of name editing in MAPS.ME

Posted by Zverik on 11 October 2016 in English.

Many mappers agree that simple and accessible editors are hazardous: the simpler editor is, the easier it is for a horde of newbies to submit wrong data. This was a main argument against Potlatch, and then iD. Now MAPS.ME built-in editor allows for changing tags and adding nodes with just a few clicks for any of our tens of millions of users. Which of course has led to a number of questionable edits.

Screenshot of the first editor with name field

The first field in any place card is name. When we released the editor in April, it was a single field for editing the “name” tag. You changed a name — the new tag value was uploaded to the map.

Complaints started coming almost immediately. Turns out, some tourists were renaming attractions to their language for easier navigation. If you look at the Questionable Edits wiki page at the time, you’ll see that names in wrong languages are the most worrying kind of edits.

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100€ for a subscription to diary comments

Posted by Zverik on 29 September 2016 in English. Last updated on 30 September 2016.

Okay, I’ve got tired of this UI, and I’m swamped with other tasks, but there is some money left from my travel to SotM. So I am announcing a grant: 100€ for a merged pull request allowing people to subscribe to comments in OSM user diaries. (NB: 300€ now, thanks to Stereo and Mikel.)

There should be a checked by default checkbox near the “Save” button (“Receive notifications about further comments”), and a button to subscribe/unsubscribe. All notifications should go to e-mail, much like changeset comments now.

When you have your pull request merged, I’ll transfer that money to your card or bank account. And of course I’ll publish a big thank you :)

The offer is not indefinite: the PR must be submitted until the 1st of November and merged before the 1st of December. And yes, there might be a competition, in that case OWG will decide the winner by merging a pull request.

OSM Stars from wiki

This Sunday, we will meet the nominees for the first OSM Award and learn who gained the most votes in each of the six categories, including Mapping and Blogging. 650 mappers have already voted, and if you have not, please head to the awards website and make your choices. All you need is an OpenStreetMap account.

The voting closes on the morning of September 22nd, when the Brussels Maptember begins with two great conferences: HOT Summit and FOSS4G.be. After that we will dive into OSM topics at the State of the Map, and on Sunday, before lightning talks and workshops, we will know the winners.

But for now, there are still ties in some categories, and your vote can decide who will get the award. Do vote now and meet us at the State of the Map!

MAPS.ME is now an editor

Posted by Zverik on 5 April 2016 in English. Last updated on 6 April 2016.

Which popular editors do we have now? According to statistics, three of these: iD, JOSM and Potlatch 2. The next four editors are mobile: Go Map, OsmAnd, Vespucci and Pushpin each have a thousand of users. Today there is another one, which now has less than a hundred users, but aims to go for the first place: MAPS.ME.

As you might know, MAPS.ME is a popular app for using OpenStreetMap data on a phone or a tablet. It has geocoding, routing (using OSRM engine), bookmarks and 3d-buildings. It runs both on Android and iOS devices, and it is very fast. Obviously it works offline: you just have to download some countries. Besides speed, MAPS.ME is known for simplicity: even I can understand which buttons to press, without examining every control and menu item first.

Just now we have released the first major update this year. It has better geocoding (and reverse geocoding), smaller regions (no bigger than 70 MB, most are below 50) and, the most important change, now it can edit the map! In most POI cards (click on a POI and get one) there are two new options: «Edit place» and «Report a problem». The first one opens a simple (as in, easy to understand) editor for relevant fields: name, address, opening hours. The second one is for leaving OSM notes. Also there is an «Add a place» option on the menu. So yes, it’s an editor.

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Почему-то информация была только на форуме, но на ближайшие дни, если хочется потренироваться в картировании города, который ещё не так надоел, как ваш собственный, загляните в тему http://forum.openstreetmap.org/viewtopic.php?id=53769