Harry Wood's Diary

Recent diary entries

Northwick Park Hospital buildings

Posted by Harry Wood on 19 May 2021 in English (English). Last updated on 23 May 2021.

Last night I sat and armchair-mapped a load of hospital buildings for Northwick Park Hospital here in North West London

Northwick Park Hospital before-after gif

I tend to follow a rule of no armchair mapping in the UK these days, but I have a few extenuating considerations where I allow myself to break that rule. This is a big hospital. It’s the kind of thing we should certainly have mapped properly across London and the whole UK. I’ve armchair-mapped quite a few hospital buildings like this in Africa after all! I wonder how many other UK hospitals are missing building detail.

Actually the omission seemed wierd to me, as if maybe the buildings had been mapped but recently deleted. I thought it looked as though somebody had swept in and hit delete but missed just one or two little buildings (that little dentist), but how to prove it? I spent some time trying to figure out if I could find deleted nodes in a very constrained bbox e.g. using Overpass date features, but I gave up. Finding deleted data is difficult.

Denying the chance for somebody living locally to take care of their map, is the micro-harm that we potentially do when armchair mapping. I started by putting a simple note, and waiting 3 months, partly in the hope that somebody living more locally might see that.

The missing buildings were actually pointed out to me by SK53 during our London virtual meet-up. I suppose this is the main extenuating consideration actually. I sort of feel like if people are having conversations about bad data, then somebody really ought to go ahead an fix that bad data. So yes… It’s fixed! Although actually I’ll drop a couple more notes where I remember aspects of the imagery being a little unclear. “Survey needed”. And of course surveying could add much more detail. Footway connectivity outside and maybe even inside. Names of more of the buildings. etc. So if you do live local… get stuck in! I wonder what’s the best example of hospital detail in the UK. Cambridge and Edinburgh can be relied upon to provide pretty good examples!

Speaking of that London virtual meet-up… we should do another one! Or maybe even a real pub meet-up again some time soon! I’m still pondering other virtual event formats too. That last one was fun, and was basically a great chance to catch up between friends. For the first few hours we didn’t even talk abut OpenStreetMap much. Later on the zoom call I thought about how to direct the conversation back to OSMLondon, and so I shared my screen and started panning around the London map at random. As expected this prompted a few conversations including SK53 pointing out these missing hospital buildings. I’d like to do something like that again. Or what’s the best map/data view to prompt interesting conversations I wonder?

Another thing: I’m still “between jobs” at the moment which means, while I’m not exactly at a loose end (With job hunting and kids I’m feeling surprisingly busy still), it occurs to me I could run some kind of virtual OSM event during working hours. Crazy idea? It would suite me a lot better actually, but would rule out most of the normal crowd I’m sure. Could be good for attracting different kinds of people. Maybe we can do both. Let me know what you think.

Update! OSMLondon zoom call scheduled for 8pm on Sunday 23rd

Location: North Wembley, London Borough of Brent, London, Wembley, Greater London, England, HA0 3SB, United Kingdom

New hyper-detailed garden fence mapping in London

Posted by Harry Wood on 18 August 2020 in English (English). Last updated on 25 September 2020.

A few days back I noticed a new patch of hyper-detailed mapping appearing on the London map here near Stroud Green Road, with gardens and garden fences all drawn in. It’s impressive! It looks amazing if you zoom in on that patch:

Stroud Green Road garden fences patch

But I felt some frustration when I first saw it, because of the old imbalance of detail issue. I don’t mean to say I’m angry with someone for adding this detail. It’s more a case of being frustrated by an OpenStreetMap problem which we collectively never solved, and I’m frustrated that I can’t actually think of a good solution!

In London for a long time the hyper-detail has mostly been about buildings data. A decade ago as I was organising regular mapping parties, I tried to encourage people to think about building data coverage and to tackle this massive mapping task in something resembling a logical order. Read my diary entry (with coordination animated map) from back in 2010. Back then the default standard style showed buildings a lot more prominently. Dark purply brown, and to quite low zoom levels. Thankfully it was since toned down to a more subtle beige but even so, buildings are very noticeable, and it looks wrong/confusing when patches of buildings appear in sporadic illogically arranged areas. (Maybe this requires a leap of empathy. Imagine for a second, you’re just looking at the map without knowing about how it’s created!)

I think we did quite well at filling in the city centre a while ago. Before that we had major buildings in the city centre missing and yet these random residential estates appearing.

It’s with this problem in mind, that I held back on mapping houses in my neighbourhood for years. Instead, when mapping locally, I focussed on mapping all the shops. These I would map with their buildings because it looks OK (logical!) to have shops showing more prominently than the surroundings.

But I’ve watched residential (i.e. all buildings) data coverage growing. It comes in patches as individuals do their areas. I remember a massive patch to the north of me all got filled out very quickly all at one. That raises an important question about armchair vs survey mapping. Personally I try to do a full addresses survey at the same time as adding residential buildings, but I always assumed that en-masse armchair mapping of London buildings would happen sooner or later regardless of objections. And I assume that was the case for this new north London patch. I’m thinking of Finchley or Barnet or Walthamstow maybe. These places with buildings but not addresses, but…

These days they’re all merging into one mega-patch ….which is what we want! And so it was a couple of years ago that I realised it was time to finally map all the buildings in my neighbourhood, because if I didn’t do it, somebody else would, and I couldn’t have that! But actually (with all the address surveying too) it’s a super slow process, and I haven’t been able to push back my “fully buildinged radius” as far as I would like yet. I do look forward to the day this patch feels more joined up eliminating some of the funny gaps to the south of where I live. With a bit more surveying effort, maybe in a couple of years time my bit of North London is going to look beautifully consistently detailed at last.

…or it would have. But suddenly a few days ago…

So you can see this is not a new problem for me to worry about, and that’s before I mention my 2011 SOTM Denver presentation in which I described the hyper-detail issue in some depth. Partly I added those slides because I was worried I might be boo’ed off the stage by the Americans if I just presented a “surveying good, imports bad” message, but this issue was playing on my mind in relation building coverage and it also relates to crazy hyper-detail coming from tagging ideas and discussions of things like mapping roads as areas. Different, but perhaps part of the same problem. Patches of imbalanced hyper-detail where it feels like we have no hope of “finishing” across a wider area, and which work against (and perhaps render impossible) the aim of achieving consistent balanced map coverage.

progressively more insane. slide

I also mention another side to the problem. “it’s a waste of time and energy of the mappers doing it, but It becomes more a problem too when people encourage others (including confused new mappers) to follow their lead”

But I say these things without suggesting a solution. The only idea I had in the direction of a solution was the following:

“This runs quite contrary to the way we’ve celebrated detailed mapping in the past, but perhaps we need to think about a new message. Among our pro-mappers perhaps the message should be: “consider the levels of detail around you”. Don’t go crazy with the levels of detail within your blossom of map coverage. Keep a cap on this and map further afield instead. Go to a level of detail which is realistically attainable by you, or with the help of other mappers, across a wider area.”

But I’m not sure how we would ever engender a new community mapping message like that, even if I could persuade more people that we wanted to. I don’t think it makes sense to be telling anyone off for adding detail. That’s why it’s a problem without a solution as far as I can see.

Anyway I thought the new patch of garden fences was an interesting reminder of that general issue, and it bugs me that this is going to be an ugly imbalanced patch of map I’ll be looking at for years to come now. However there’s a few thoughts which make me feel better about this:

Firstly in the twitter conversation about this, people pointed to Edinburgh where there has been loads of garden fence detail added in recent years. Always inspiring to see people getting on with it and proving it can be done. And what I think they have done well at, is that thing of adding the new detail logically in a centre-going-outwards formation. That feels important to me, thinking from a user perspective. For example a map user may look at the imbalance of detail here asking themselves “why does one side of House O’hill Road have those details, and not the other side?” but zooming out, an answer becomes apparent. Even if we don’t like the missing data, we can see the logic of houses more central within the city having more map data. The coverage is clearly expanding westwards. Looking at the extents of this map detail, you can see that the Edinburgh community have done reasonably well at working outwards from the city centre. Some good coordination. It can be done!

Secondly, it occurs to me actually that the stark difference in detail level my eye is bothered by around Stroud Green Road, is mostly due to missing buildings coverage. It does make me think the gardens mapper should’ve done more of that first but I also realise if I can map more buildings, or if the patch of mega-detail spreads over areas of missing buildings, then the imbalance will be lessened. The garden fences detail makes the map a look a bit different, but when zoomed out it really just shows up as a hint of extra green from the gardens, comparing with buildings-only coverage. Not so imbalanced. It’s motivation to get more buildings mapped!

Thirdly, although we might think of garden fences as a next-level upping the ante on detail level, and naturally part of me is worrying “should I have been surveying to that level of detail all along? Am I going to have to go back and re-do all those houses?” …you can’t actually survey garden fences very well anyway. I suspect the reason this particular kind of detail has suddenly appeared in 2020, is more to do with the bumped up quality of bing imagery we’ve seen this year. I think this means that (when the time comes) I, or somebody else, can reasonably go back to any residential streets I’ve already mapped, and sketch in the garden fences from bing. No need for special surveying. There’s some exceptions to this logic. Places where you can see garden fences on-the-ground, and where mapping them accurately may be significant, but actually I’ve often been mapping them in those kinds of places anyway. e.g I’d put a wall like this to illustrate the pedestrian non-access situation. Maybe it’ll be a big armchair mapping exercise in years to come to even out the coverage of gardens with garden fences.

Long Names Of OpenStreetMap. 2019 update.

Posted by Harry Wood on 1 August 2019 in English (English).

I updated the “Long Names Of OpenStreetMap”.

theatre example

Now there are 722 long names, that is, objects with a name longer than 150 bytes.

I haven’t run a full update since October 2017. Back then there were 464 long names. So I guess we’re getting worse at keeping our names short.

It looks like bus routes with very long name values are becoming more widespread. For example here is the “391 “B”: Veresegyház, Misszió Egészségügyi Központ => Veresegyház, Dukát utca => Veresegyház, Cserje utca => Veresegyház, Eötvös utca => Veresegyház, Újiskola utca” bus route. Snappy name!

Maybe I should’ve limited by character count rather than bytes. Cyrillic scripts are at a unicodey disadvantage, not to mention chinese.

Not all of them cause wacky rendering like the theatre example in the screenshot above (node).

I do think they all have something in common though. Using the name tag for something which isn’t really a name.

There’s some more details and comments on my original diary entry about this. From a tagging policy perspective there’s a discussion (so far just between myself) on the wiki: “Very long names. bad practice/bug?

A little shop contact page ...with OpenStreetMap

Posted by Harry Wood on 5 June 2019 in English (English). Last updated on 6 June 2019.

A rare thing happened with some shop mapping I was doing just now. I was adding “HOM Concept” from my Mapillary view out of a bus window. I looked up the website of the shop …and look! OpenStreetMap!


Actually it might be the first time I’ve ever come across a contact page for a small London shop (just a few branches) as I was mapping, and found an OpenStreetMap map.

I have noticed OSM maps popping up around the web more and more lately. That’s something I’ve always pondered ways of encouraging, dreaming up quite a few different angles on the challenge of attracting web developers to use OpenStreetMap, but I guess it’s predictable that the thing which really shifts them off google maps is google maps themselves, as they start getting more strict with charging for high traffic.

I find it significant to see something like the HOM concept website using OpenStreetMap because it’s a very small organisation. I guess they will have paid somebody to do a quick web-design job for them, and that somebody has chosen to quickly do the map with OpenStreetMap, which is great to see! Also great to see not-the-standard OpenStreetMap tiles, both from a tile usage policy point of view (We want web developers to get maps from a diverse range of tile servers, not always hitting one central OSMF hosted server) and because the choice of a black ‘n’ white style (wmflabs tile server) with a yellow marker fits rather well with their colour scheme.

There’s a few not so great things. Some folks will have already spotted the lack of OpenStreetMap credits. In fact they seem to have accidentally covered them up with a black box. It only happens if the browser is wider than 1060px actually. Otherwise the layout is completely different and the normal credits appear on there. This black box is some weird scroll progress bar widget which seems a bit pointless. So that’s annoying, but we know people make mistakes like that. What else?…

Call me a stickler, but I feel a contact page map marker really should point at the right place… like really… I find it quite unfathomable that someone would put together a map for users to find a business, and then put the pointer in the wrong place! And yet I’ve seen it a lot. One cause I’ve noticed is that some google map widgets can be set-up, not with coordinates, but with a geocode happening every time on an address or postcode, which obviously might then be a little off (even so, you’d think the web developer would notice this and think maybe it’s something they ought to find a way to fix). That’s not the case here. They’ve just coded coordinates in the wrong place. Should be more like 51.58697/-0.10138.

But while we’re looking at the marker position, d’you notice something else funny about it? This is another thing I notice web developers getting wrong a lot. Never with google maps. Always with leaflet. I’d like to say it’s only a mistake made by novice web map developers, but I had to point out and fix the same mistake on the map marker of the State Of The Map website last year. Is nobody else noticing this? Well maybe I’ll leave that as a puzzle for you, because I think it deserves it’s own separate blog post.

It’s fun to grumble about other people’s web map mistakes. But it’s more fun when people mess up using google maps. On the whole my primary message to “HOM Concept” web designer would be… “Yay! OpenStreetMap!”

Using Rob Whitaker's tool to map UK Public Rights of Way

Posted by Harry Wood on 25 September 2018 in English (English). Last updated on 20 November 2018.

We’re coming to the end of the UK quarterly mapping project on footpaths.

The designation=public_footpath edit tracker

…is running for just 5 more days. So last chance to get on there UK folks! This is all about our UK system of legally designated “public rights of way”, so if you’re elsewhere in the world you may stop reading now.

You may notice that I only just became a new starter on there myself! This is partly because I found it a bit tricky to understand what we’re supposed to do, but I finally sat down and figured it out at the weekend. Sorry it took me so long, but better late than never, here’s a few quick pointers:

Use Rob Whitaker’s PRoW data comparison tool. There’s a list of regions where he’s managed to get PRoW data.

Drill down to regions -> districts -> borough. You might pick where you live, but not everywhere’s on there. Failing that, try to find somewhere you know. Failing that, I guess it doesn’t matter where you pick.

Now you’ll see a map with lines. Here’s a bit of Watford


The lines appearing on this map are different colours for different designations. Yellow for footpaths, blue for bridleways etc. More importantly they are Thin: done, Fat: todo. So in the above image I have done the long footpath through Cassiobury Park on the left, hence that yellow line turned thin. The rest to the right are fat lines still to do.

What does “done” mean? Well the lines actually represent local council GIS data. It’s where the council thinks there are footpaths, and where they have official designations as such. Each one has a reference number.

Click the line to reveal the official reference number. Copy that whole title, and put it as the value in the prow_ref=* tag. For example this path has “prow_ref=Watford Borough FP 30” (including space characters)


The designation=* tag is easier. It’s just one of public_footpath, public_bridleway, restricted_byway, or byway_open_to_all_traffic. Those are our longhand OpenStreetMap values. The official data uses the more compact codes: FP, BR, RB, BY.

So these tags go on the corresponding way in OpenStreetMap, where “corresponding” means all the ways which seem to match exactly or almost exactly with where the path runs in the official data. You may need to set the same prow_ref on several little footpath ways. You may need to divide a long footpath way to match just the length where the prow_ref applies.

If there is no corresponding way, then this is interesting. Maybe you’ve found something missing in OpenStreetMap. Maybe you’ve found something wrong in the official data. Time to dig deeper, or flag it for somebody local to investigate I guess. As the page states, we should not blindly copy the geometry data into OSM from the council GIS data. The page also states the source tag to use on your changeset for the particular district you’re looking at. (e.g. in Watford it’s source=hertfordshire_county_council_prow_gis_data on the changeset). In fact in general the page gives lots of information which is worth reading through. I’m essentially trying to give a summary here. Did I get it right?

So this whole thing is an exercise in ticking off matches with this 3rd party data, by adding in the prow_refs. Like any process of ticking things off, there’s a certain satisfaction in getting it done in an area I guess.

But I have to say (after all this) I haven’t found it all that interesting or addictive to do myself. There’s obviously lots of this matching to do as an armchair mapping exercise, but it would be more interesting to do in an area if I knew it better. I’d probably enjoy doing some bits of West Yorkshire, if that was available. But also it feels a bit like littering our data with 3rd party arbitrary reference codes. prow_ref values are certainly not verifiable on the ground! And they’re “official”, sure, but I’ve come to associate “official” government data in OSM as shoddy quality and limited value (Seemingly the opposite of what many folks think official data is)

I guess the value here is in ticking things off, whittling down towards finding those interesting cases where we might be missing a footpath. So 5 days left. The choice is yours. Go wild adding those prow_ref & designation tags… or don’t :-)

Fixing multipolygons for the renderer

Posted by Harry Wood on 4 September 2018 in English (English).

Just thought I would re-iterate something imagico blogged about. Some important features may have disappeared from the map near you. You should check! Use the OSMInspector “Areas” view:


Generally the pink things are more serious data bugs on there I think, and they’re worth fixing because it could be a big building, or local park, or some other important feature which may have recently disappeared. This is due to a change in the renderer. It’s an improvement, but it means it is being more strict about these data bugs, so we need to fix them! (Yes we’re fixing for the renderer, but these were worth fixing before because other systems will always have struggled with this data)

But these bugs generally involve the dreaded multipolygon relations, which are not the easiest thing to get your head around. I took a look just now and found quite a variety of different problems. Some fairly easy (e.g. this one just needed an “inner” way joining up properly to make the whole building re-appear)


…some not so easy. Problematic relations can be overlapped by other ways. Sometimes the multipolygon isn’t necessary at all (created by mistake perhaps). In that case we should take the chance to convert it to a simple closed way, to make life easier for everyone …but that can be a fiddly process in itself.

So I’m inclined to say we need to pro-mappers to attack this task. But being “pro” is all relative. Most mappers are probably like me. I’ll happily wade in and try to tackle such things up to a point, but then sometimes I hit such a tangle of data, I just throw up my hands and think to myself “either somebody has thought carefully about this data, and there’s a reason it’s like this, or somebody’s made a mess, or maybe both… but I can’t tell” at which point I’m quite happy to leave it and move on to find an easier bug to fix.

So get stuck in! There’s quite a lot to fix:

I wonder if there’s a way of knowing where the BIGGEST multipolygon bugs are.

London OpenStreetMap Q&A

Posted by Harry Wood on 9 March 2018 in English (English).

I don’t think anyone blogged about London OpenStreetMap Q&A events yet, but we should! We’ve been experimenting with this new event format in London. Well I haven’t. I’m still setting up occasional pub meet-ups, but thanks mostly to Firefishy’s organisational efforts, we’ve been escaping the pub, and doing something a bit different.

These are presentations evenings, and also (trying to be) an opportunity for discussions and questions, and getting help with mapping or using OSM. We’ve had a few now. They’ve been pretty successful, with increasing attendance each time. On Wednesday night we had maybe 30 people attending.

I’ve been forgetting about the FOSS4G UK conference, which was taking place Thursday and Friday. We missed an opportunity to advertise our thing as a warm-up event to that. Some people figured it out though. Janet Chapman was going on to give a similar talk at the conference, and there was at least one other person who was visiting the UK for FOSS4G UK, and taking in our event beforehand.


Janet Chapman gave the first talk “Crowdmapping rural Tanzania to help end Female Genital Mutilation and aid development” (Crowd2Map Tanzania). Janet has been well meshed into the London Missing Maps humantarian mapping crowd, and her talk was describing all the various tools (tasking manager, field papers, mapswipe, etc) which she has adopted to good effect for this ongoing Tanzania project. You can join in with this work via ‘Tanzania’ on the Tasking Manager. But this is a great example, not just of humanitarian mapping from afar, but of tight collaboration with the locals. The local activists who are tackling the FGM in Tanzania, seem to be seeing the mapping feedback loop. They’re joining in with contributing data, (on-the-ground gathered data. The good stuff!) because it makes the maps more useful in the areas they are operating in.


Nick Whitelegg talked about a topic a bit closer to home, “Using OSM for countryside mapping”. The rendering on his website, is designed for country footpath users. It colour-codes the paths by their legal classifications. In particular the designation tag is important, or at least it is important in the UK if you want to understand the legal status of footpaths. Nick has been involved in OpenStreetMap since pre-historic times, and in his talk (which went into some technical detail) he described how was intially displaying maps built upon the OSM API before OSM offered planet dumps!. He was in this game early! Certainly I remember as a feature of the early OpenStreetMap landscape. Nick himself joined the project in 2005!

After those talks we had a little bit of time for a group discussion. I wasn’t sure if this was going to work well, and I had been writing down some ideas for discussion points, worrying that discussion flow might not be forthcoming. No need to worry though…

We had one question/observation from a chap called Will who said he was new to OpenStreetMap and found contributing via mobile apps wasn’t as easy and approachable as he would have liked (although techy himself he was looking for an easy experience to recommend to less techy friends). That was all we needed to trigger a lively group discussion with ideas for app recommendations, ideas for making things easeir, ideas about whether mobile apps are a good way to start, all of which burned through the time quite easily, and we had to continue discussions in the pub.

Additionally we had a good long period before the talks started, to chat amongst ourselves. I was trying to advise someone on options and software choices to solve a particular map usage problem. Trying to help people with their map-based projects is one of the main ideas of the event, and the reason for calling it “OpenStreetMap Q&A”. I’m not sure we’ve figured out the idea format for making that happen yet, but it does happen just with getting people in a room together (with pizza)

Huge thanks to Firefishy for organising and to WeAreFriday for hosting this event! The next one is already being pencilled in. It may happen on the 2nd of May. Join the meet-up group to keep track

Location: Clerkenwell Green, London Borough of Islington, London, Islington, Greater London, England, N1, United Kingdom

Zoffany Street

Posted by Harry Wood on 30 October 2017 in English (English).

I just added Zoffany Street to the map in more detail (all buildings and addresses):

Mapping Zoffany St animated

It’s a very short little street. A modern block of apartments on one side, and old cutesy coloured houses on the other. Relatively unremarkable except…

on flickr

UK geonerds may recognise the name, because Zoffany Street was the last street in the “A to Z”. You can read ‘From Aaron Hill to Zoffany St’ bbc article, and many other tellings of this story, but very briefly… The A-to-Z road map of London was first created as a one-woman effort by Phyllis Pearsall. Annoyed about lack of detail/usability in other maps, she decided to do a crazy thing. She went and walked all the streets of London and created her own new map from scratch. Sound familiar? Phyllis Pearsall died 8 years before OpenStreetMap was born, but she surely would’ve enjoyed those first London mapping parties.

In that original A-to-Z atlas, Zoffany Street was the very last street appearing in the index. London got bigger, with more Z’s in there since, but originally Zoffany Street was the final “Z” in the “A-to-Z”! So good job I’ve mapped it properly now.

Location: Elthorne Estate, London Borough of Islington, London, East Finchley, Greater London, England, United Kingdom

Adding vector tiles to the components diagram

Posted by Harry Wood on 25 July 2017 in English (English).

A few weeks back I gave a talk in London which was a sneak preview of my “Diagrams Of OpenStreetMap” SoTM talk Yes! I’m heading to Japan for the conference soon! I’m the only one from the London crowd going, so this wasn’t a spoiler for anyone in the audience, but this diary entry is a small spoiler. I thought I’d give some details of just one diagram from the talk. This one:


You may recognise it although I think its “Component Overview” home on the wiki is a bit hidden away these days. But anyway you wouldn’t recognise the right hand side because this is newly redrawn as of last night! In fact I’ve done a few iterations which I am unveiling as part of the talk. The left hand side editors were given an update, but last night I was tackling the more tricky right hand side where we try to show different rendering stacks and map display approaches available and used in the wider ecosystem.


Up until last night this simply described one possible “TileMill” set-up. That technology is a bit obsoleted by Mapbox Studio these days, but more importantly it’s only one of a range of new tools. So to iterate on this, redrawing a little bit, I’ve aimed for a more high level summary of tech concepts on the right.

A key new technology concept which is very much part of this landscape now is “vector tiles”. Been around for a long time of course, but these days lots of folks are making very practical use of OSM vector tiles within commoditised rendering stacks and other tools. Time to bring it into the diagram. Hopefully I’ve connected things up reasonably correctly. Vector tiles can be used as a data source fed into good old raster tile rendering, but they can also be fed direct to the browser to be displayed there instead of raster tiles. That happens usually still with the use of LeafletJS via tools which I’ve collectively called “Vector plugins”

That’s my understanding. But I’m a little unsure of the details. The level of abstract summarisation here is avoiding the details, but I would like to see a diagram which shows more specific technologies. Probably a different diagram, rather than trying to add it all on here. Something with boxes for: Mapbox studio, Mapbox GL, Tangram, Tangram Play, ThunderForest’s stack, OpenMapTiles stack, and the different vector tile formats, schema formats, style sheet formats, etc, etc. A layered diagram summarising all things vector tiles. That’s a difficult diagram for me to draw, because I am shaky on the details and generally finding some of the linkages unclear, but maybe that’s a clue that this will be a useful diagram!

Maybe I’ll create something myself in time for the conference, but maybe not. Do let me know if you know of any existing diagrammatic efforts in this area. In fact let me know if there’s any diagrams you think deserve a mention, whether on similar tech topics or something completely different. I’m ruling out auto-generated “visualisations” from my definition of “diagrams”, but other than that it’s wide open to all sorts, and I’m hoping to give a bit of a tour of a wide variety of “diagrams of OpenStreetMap”.

Mapping Grenfell Tower

Posted by Harry Wood on 12 July 2017 in English (English).

A month ago the Grenfell Tower fire happened, killing >80 people. Back in 2009 we did an OpenStreetMap mapping party near Latimer Road, and I remember mapping the area around Grenfell Tower.

Grenfell Tower as it was in 2009 - cc by-sa, R Sones

We were quite adventurous with our mapping parties back then, often travelling to corners of zone 2/3, meaning somewhat outside of central London, where the landscape is various flavours of urban, not quite suburban. This particular area always stuck in my memory as one of the most starkly mixed wealthy and deprived, or as I put it at the time “concrete estates and super-posh georgian terraced houses strangely existing side-by-side”.

Well ok so if you read exactly what I wrote at the time, I may have described them as a “horrible bunch of dodgy concrete jungle housing estates”, which seems harsh and insensitive in retrospect, but I did form an impression of the area which included some sort of admiration/pride, thinking it’s cool that we live in a city where rich and poor communities live side-by-side.

It was strange and tragic then to recognise the area on the evening news, and to see reporters remarking on what a mixed area it is. The fire was a huge screw up from several more pragmatic angles, but thinking philosophically, it feels like a failure of London to bridge the wealth divide.

But never mind wider society, what about OpenStreetMap?! I think it’s great that my OpenStreetMap adventures have lead me to explore this kind of neighbourhood, although in truth I don’t think I actually surveyed Grenfell Tower up close. I think I remember deciding to stick to the more pleasant mews to the south and didn’t venture round the back to the base of Grenfell Tower. While I appear to have notched up the first version of the building in the editing history, I think it was just pre-sketching from Yahoo imagery, and viewing it from a distance.

As has long been pointed out by Muki Haklay in his academic research (e.g.), OpenStreetMap doesn’t always succeed in “democratising” to the extent we’d like. After all we’d really like the people living in these estates to map them for themselves. Even so, an OpenStreetMap mapping party got me out exploring these areas of London I wouldn’t otherwise have visited and wouldn’t otherwise have paid any attention to.

Location: Lancaster West Estate, Royal Borough of Kensington and Chelsea, London, Shepherd's Bush, Greater London, England, W11 1WG, United Kingdom

Wenlock Arms January (+ Blue posts tonight!)

Posted by Harry Wood on 21 February 2017 in English (English).

We’ve got an OpenStreetMap London pub meet-up tonight!

We’re managing them approximately monthly these days, so last month we had a pub meet-up to kick off 2017. We went to the Wenlock Arms. It’s a nice little pub which almost got demolished but was saved after a campaign. Now with all the big new buildings around it reminds me of the very last scene of Batteries Not Included. But they have modernised a little. I remember their rather sparse pub website used to link to OpenStreetMap, but sadly their website was since rebuilt by some boring web designers with boring google maps.

I remember it used to be good for real_ale=yes, and that was certainly there still. Crazy strong stuff. Luckily I’d stuffed myself with fish n chips before arriving because food=no! But it does have real_fire=yes!

on the wiki

(Another photo for the real_fire=yes tag)

So with strong beers and a glowing fire we quickly got chatting about all things OpenStreetMap. I’ve lost my notes, but I remember meeting Scott Davies and talking about Australia and Walthamstow. And meeting two guys from Geolytix who I keep hearing about via Open Data Institute connections. They provide data on ratail outlet locations using OpenStreetMap among other sources.

Good to have some new folks along. If you fancy joining us for the next OpenStreetMap London pub meet-up… it’s TONIGHT at the Blue Posts. All the details on the London wiki page. You can also sign up on if you fancy it. If you’re not sure how to recognise us, the above photo will give you some idea, but it’s a good idea to turn up a bit late (like 7:30 onwards) By then we should’ve assembled in our maptastic huddle. I’ve got my hi vis jacket with me to today, and I’m sporting my navy blue SOTM 2016 T-shirt in celebration of the fact that I’ve got my flights booked for SOTM 2017!

Location: Hoxton, London Borough of Hackney, London, Islington, Greater London, England, N1, United Kingdom

The OpenStreetMap awards, and writing about people in pubs

Posted by Harry Wood on 22 September 2016 in English (English).

I was meaning to say (and left it a bit late) it is a great honour to be nominated for the OpenStreetMap awards.

I have realised recently, with some embarrassment, that despite trying to contribute in many different areas, my greatest contribution to OpenStreetMap has almost certainly been my diary entries about people sitting around in pubs! :-)

montage of OpenStreetMap pub photos


I think my pub diaries date back to 2008 some time. I started writing them as a way to promote our London meet-ups and also to try to inspire others to run similar events worldwide. Hopefully it succeeded in that aim to some extent. But it also developed into a sort of newsletter with a mixture of sometimes current, sometimes just random, topics in and around OpenStreetMap, mixed with some of my own half-baked opinions and opinions of others around the pub table …if I agreed with them ;-)

It turned into quite a habit, which I felt I should keep going. I even became quite organised, by actually writing notes in the pub. I adopted a sort of stream-of-conciousness writing style. Nothing too polished. I think this helped make it a bit less effort, but even so, it added up to quite a lot of effort over the years. It’s nice to have this recognition of my primary OpenStreetMap talent: writing about people in pubs!

I think that Zverik has done a great job putting together these awards. It’s an idea I’ve pondered in the past, but never got off my ass to do. I hope they’re considered successful, and become a regular annual fixture to recognise more people within our community. Hopefully it will motivate people. Hopefully it won’t make people feel resentment. Probably it won’t do either of those things all that much, but…

I think it feeds nicely into another positive effect. Thinking about OpenStreetMap “storytelling”, things like this create a “human interest story” where previously we may have missed it. Take the “core systems” category for instance. We spend a lot of time talking about technologies like Nominatim, iD, osm-carto, OverpassAPI, etc, but if we can find a way to spend more time talking about Sarah Hoffman, Bryan Housel, Mateusz Konieczny, Roland Olbricht, Grant Slater and Tom Hughes, this not only gives them some much-deserved kudos, but it makes the story more interesting somehow. In our open community we miss out a bit on this by being so egalitarian, altruistic, and just plain over-modest all the time!

Other fantastic efforts which create a human interest story include the Belgian community’s “Mapper of the month interviews”, and the OpenCageData interviews. I’m a huge fan of those. Again, it’s a thing I pondered about doing but never got off my ass and did it. I think we need to weave a bit of this good stuff into the somehow.

In fact thinking about doing things on (and generally not doing them) has put me in a state of analysis paralysis lately. My stream-of-conciousness diary entries dried up, and so I’m also rather embarrassed to be nominated for an award for a thing which I’ve stopped doing!

Of course I also have a new and exciting time sink these days, but I am allowed a few days off from nappy changing to head to State Of The Map Brussels (arriving tonight). I’m looking forward to this immensely. Maybe I’ll get into some interesting conversations with belgian beer! If you like my diary entries, maybe I’ll write up some of these conversations. There we go… it’s motivating people already!

Long Names of OpenStreetMap

Posted by Harry Wood on 31 August 2016 in English (English). Last updated on 1 August 2019.

Check out this thing which I just got working again:

>>> Long Names of OpenStreetMap <<<

So that’s elements with a name tag, where the name seems to be very long. It’s a full list of the longest names in the planet (>150 chars)

I just found this old code and dusted it off. I made it originally back in May 2010 when Richard Weait ran a “Project of the week” looking at long names. I called it “namecheck” at the time, but I’m renaming it “longnames”.

A crazy long name is probably a data bug to be fixed. It certainly looks like a bug when we try to render it.


But… well taking that example. Here we have a few university buildings, each with a name, which list several departments. Can we class this as wrong? I think so, yes, but I’ll have to make a hand-wavy non-scientific judgement: I’d say it ceases to be a name of the building and becomes more of a “description” when it gets that long…. in this case. And maybe that’s a problem for a lot of them.

But in general this is not going to be a clear case of “these are all bugs. Here’s how to fix them”. Because of that I think I would stop short of saying this could be a MapRoulette challenge, or a new class of bugs for KeepRight or Osmose. For the moment I’m just going to put this list out there, and suggest some careful interpretation (but feel free to suggest other actions / tagging policies in the comments)

On the other hand some of these definitely are bugs with clear fixes. I saw somebody adding a load of space characters and then repeating the name again within the name tag, presumably in attempt to control label placement on a road (Yeah no we don’t do that)

The other caveat, in case it wasn’t clear, the username listed there is ‘last editing user’. It’s not necessarily the person who added the very long name, but it is a person who didn’t fix it :-) That and the last edit timestamp are really just to see if there’s any interesting patterns in the list.

My planet crunching script to find long names is here along with SQLite, CSV, and mangled OSM XML output files. I will re-run it again in a week, but the display also has a (slightly odd) feature to let you “rescan” an element after you’ve made a fix.

[Update: I mentioned “feel free to suggest other actions / tagging policies in the comments”. But also this discussion on the wiki might be a good place to discuss debate what the policies should be]

[Update: New diary entry. Updated data for 2019]

Tree named pubs of London

Posted by Harry Wood on 30 May 2016 in English (English). Last updated on 1 June 2016.

It’s London Tree Week. I saw someone tweeting at OSMLondon asking “Can you help identify tree named pubs In London?”. Why yes I believe we can! We’ve always specialised in pubs. We even used to have a tree named pub “The Mulberry Bush” as one of our OSMLondon regulars.

This seemed like fun, so I went ahead and did it. Here’s the tree-named pubs of London on a map.


My method was maybe a bit old these days. See this bash script which fetches the London metro extract, uses osmosis to get pub nodes, then pub ways, then merge pub ways and nodes, then uses osmconvert to get centroids on the ways, then convert to CSV. Then grep to filter ‘Bush’, ‘bush’, ‘Tree’ and tree’ (but not ‘Street’) [Update: I’m now also finding tree type names. See comments below], to result in treepubs.csv. After that I fiddled with the CSV to make it a javascript array, and loaded that into my leaflet marker array example, and loaded in the treepubs as markers. Job done.

I found that to be the easiest way to do it, having done similar things before (This old blog post describes similar osmosis/osmconvert steps for example) …but there’s probably many different much easier ways of pulling up a map of tree-named pubs in London (or at least getting as far as the csv output). So that’s an exercise for the reader.

I’m quite sure we should be able to do a single Overpass API query to get the pubs of London (as centroids for ways).

I once saw a talk by people from Tableau (GIS software) Visualising the Great British Pub with OpenStreetMap data and Tableau which was all about mapping pub names. They could get it done that way for sure.

Pub names are always fun, but we should probably look to do something more directly related to London Tree Week. We have a lot of trees mapped in London. Maybe we should visualise this. Make a dedicated tree mapping app or something. No doubt London’s tree data is still skewed towards Southwark where we’ve got them all imported. Tree mapping party anyone?

Mapillarising Brazil

Posted by Harry Wood on 15 May 2016 in English (English). Last updated on 17 May 2016.

For years I’ve been meaning to try out Mapillary properly, but my phone is broken and can’t connect to wifi, so no upload.

But this was another thing I got to do while on holiday in Brazil. I persuaded my wife to install mapillary on her phone, and we mapillarised while we were driving around her home city of Guarulhos. She’s pretty bored of all this mapping stuff, but likes to keep me entertained while we’re in Brazil, and maybe she likes the idea of mapping her home town too. So we got lots of photos around these colourful Brazilian streets.


Also while going on a trip to the seaside, but sadly I don’t think I got much of a seaside view in any mapillary photos. Some are quite nice and jungly though


And on the way there my wife wasn’t amused when we got massively detoured in a drive around the city of Mogi das Cruzes. It was only semi-deliberate :-)

On the site you can see what proportion of streets have coverage (green) on a map display like this. I guess Mapillary coverage is expanding, but there’s a long way to go. Hopelessly incomplete… but maybe if enough people join in, we’ll have street-level photos of every street in the world. It feels like exploration. Conquering the territory, or laying the first tracks to form a skeleton that others will build upon. It feels like the early days of OpenStreetMap.

I was impressed by the ease of photo data gathering with the app. It’s a very passive process but the app gives satisfying flashing counter as it gets photos. It detects when you stop moving and stops taking photos. The messages makes it nice and clear what’s going on.

We were driving. I’m not sure how well it works with pedestrian tracing. By fortuitous coincidence, I was gathering up freebies at SmarterTravel Live conference, a few days before heading to Brazil, and one of the freebies (courtesy of dat mobility. Thanks!) was this simple windscreen mounting sucker thing. Perfect for mapillary tracing!


I was also impressed by the ease of upload. (Given a wifi connection) it’s very simple to upload this quite hefty amount of data to the mapillary servers. There’s then a delay while mapillary crunches the data before you see your green line on the map. I notice there’s then a further delay before the images get stitched together with the animated zoomey effect. Understandably because it’s a huge amount of processing, which no doubt gets queued up along with everyone else’s collections of hundreds of photos.

But what about using Mapillary for contributing to OpenStreetMap? When pondering OpenStreetMap workflows, I see a sliding scale of more or less passive data collection. Mapillary is hugely passive, which is great news when it comes to quick effortless surveying, but the flip-side of that is, you leave a lot of work to do later on when you’re back at the computer. I did a bit of this last night. Looking through the places we’d been driving around Guarulhos, clicking around with the mapillary JOSM plugin. Click next photo -> next photo -> next photo, which is essentially like driving along the road all over again, but this time I’m scrutinising the photos for anything I can add to the map. Probably a lot slower than the drive itself (depending on how much stuff you see which needs adding). In other words, after all that very simple passive surveying, I’ve left a lot of work to do later. A hopeless amount really

Being in Brazil my photos are all super-sharp in the harsh sunshine, however I found it pretty hard to identify Brazilian highstreet shops. In the more shabby areas the shops are not clearly branded or labelled (akin to the shabby north London shops all around me), and I often looked at translating a shop sign which turned out to be a billboard/product advert. Slow going, and I probably won’t get around to examining all my Brazil mapillary traces for data to add to OSM.

But being shared with everybody, a mapillary trace is a resource which has the potential to be super-useful for other OpenStreetMappers. I’ve already used other people’s mapillary traces in London on a few occasions e.g. puzzling over particular data problems from notes or other QA tools. But mostly I’ve found myself wishing there was more mapillary coverage. When we get to the point where we can back-up all of our data fixing with both aerial imagery and street-level photos, Mapillary will be quite something! …might have to borrow my wife’s phone!

School Edit Tracker

Posted by Harry Wood on 28 April 2016 in English (English).

The “UK quarterly project” for the start of this year, was about schools. It was pretty popular and quite a few mappers got involved in editing and fixing up schools data in the UK. How many? Well…

I fired up my old “edit tracker” code to track School edits during the first quarter, and now it’s frozen as a record. So we can see 362 people did a total of 15548 edits to UK schools data during the quarter.

And here’s the rankings, showing that Robert Whittaker takes first prize with 1339 edits. The rankings also show a classic long tail curve. Not too uneven, but still with almost half of our 362 people only making a single school edit. But that’s OK. Getting lots of people chipping in a little bit is a good thing.

That’s why I created a new display called “New Starters”. I hoped this might get people interested in the challenge of how to spread the word and get more people joining in.

Linked from there, and from the rankings, I made another new display for each user. So here’s the school edits for the ‘Harry Wood’ user for example. We can see edits over time, so we can see my rather meagre contribution. We can also see that Robert Whitaker had a spurt of activity towards the end, while Yorvik Prestigitator seemed to take a break at the end, (and actually this allowed Robert to sneak ahead and take the top spot!)


This involved a bit of drawing of bar charts in javascript. Last time I did something like this, I generated static images using google charts API, but this time I wanted the interactive mouse-over effect which we see with so many web charting libraries these days. I just had to find a free open source one… which presented quite a big sorting the wheat from the chaff challenge. I chose c3.js, which was quite easy to get working for this. Sometimes the width of my bars goes a bit wrong. Look at the way they overlap on the this chart for example. Maybe someone can spot what I’ve done wrong. The source code for all this display logic is on github.

Behind the scenes, there’s my “diffreader” logic. As the name suggests, it reads the diffs (OpenStreetMap minutely diffs) Some ruby, a bash script, and sticky-tape, doing all the fuddling around with diff files, sequence files, parsing XML badly (really badly Naughty Harry), and eventually writing a nice SQLite DB file full of school edits meta-data. That’s all unchanged from back in the days of wimbledon edit tracking, and the Big Baseball project, but one big thing I had to add was the ability to isolate UK edits. Easier said than done because the diff XML will sometimes contain nodes, which have latitude and longitude… sometimes not. I think if you edit a school by only changing its tags, then it doesn’t. So I had to make some other calls in some circumstances, hold onto some data which was read in from earlier in the file, and generally apply more sticky-tape to my code. …Quite a lot of hassle just to decide if an edit is in the UK.

It all works pretty well though. I was hoping to point people at it a bit more (tweet about it etc) to whip up some competitive excitement in the closing few days of Q1 …but then I was busy on a beach in Brazil :-) Actually I don’t have a way to stop it automatically, so I had to remember to shut down the cron job at midnight UK time on March 31st, but as it happened I was also busy online getting an april fools blog post put together at the time!

The “UK Quarterly Project” is a thing the mappa-mercia guys have been running for quite a while now on their blog. I think Brian Prangle has been the main man behind them. There’s been quite a few. I rejiggled the ‘UK quarterly project’ wiki page to list them all. But I think after all the excitement of editing schools, we’ve not announced a topic for Q2 yet (unless I missed it). I’m keen to see if it will be something I should unleash this edit tracker tool on again.

A missing zoo!

Posted by Harry Wood on 11 April 2016 in English (English).

I just got back from a holiday in Brazil. We were over there with the new baby, so we hadn’t planned anything too ambitious travel wise. Just visiting the family in São Paulo. I should say in Guaruhlos, which is a smaller big city inside of, or outside of the massive city of São Paulo, depending on who you ask (It’s really all part of the same sprawling concrete jungle)

So I didn’t manage to organise an OpenStreetMap meet-up this time, but while changing nappies and bumming around on the internet I took at a look at the attractions of Guaruhlos according to various internet listings. There aren’t many, but there is… a zoo! My wife didn’t even know about it and neither did wikivoyage… neither did OpenStreetMap :-O

Of course I insisted we go there, and so now, to my surprise, I have had the opportunity to bag a missing zoo in OpenStreetMap! Naturally I also had to map out all the different animal cages. That’s the standard OpenStreetMap zoo treatment which the Berlin Zoo mappers started I think. I haven’t mapped the details quite down to Edinburgh Zoo levels, and some of my positioning of things under the trees may need a bit of tweaking, but… behold Zoológico Municipal Guarulhos!

Zoológico Municipal Guarulhos

The tag for the different zoo animals seems to be tourism=attraction + attraction=animal. and the name tag for the name of the animal of course. Which would be weird if you just plotted a map of where all tourism=attractions are :-) I put Portuguese names in (from the zoo signs) but also name:en tags so you can have an english map of the zoo if you want.

I also added the zoo to WikiVoyage’s ‘Guarulhos’ page. WikiVoyage has some quite nice OpenStreetMap integration these days. You can easily set coordinates on all the listings, and they appear on a marker map. Not sure how long that wikimedia base-map takes to re-render, but… tourists don’t visit Guarulhos very often. When they do, we’ll be ready!

I’m back in London now without my wife and baby for two weeks. I’ll miss them terribly of course but… I’M FREE! Time for some London pub meet-ups!

Location: Jardim Rosa de França, Vila Galvão, Guarulhos, Região Imediata de São Paulo, Região Metropolitana de São Paulo, Região Geográfica Intermediária de São Paulo, São Paulo, Southeast Region, 07081-060, Brazil

OpenStreetMap and Humanitarian OpenStreetMap Team Together

Posted by Harry Wood on 30 November 2015 in English (English).

Amazing what some professional video editing can achieve. I had a fairly long waffling chat with Jonathan Cronin, and he’s sliced out the good bits, overlaid some photos, etc, to turn it into this video:


In the background behind me is the Future Cities Catapult offices where I work some of the time. Some of the cutaways are to itoworld’s animated edits globe videos

Of course, he’s also interviewed Ivan Gayton from MSF. (Incidentally I recently posted my own video of Ivan as he described the Kunduz hospital bombing at a missing maps meet-up. Zero attempt at editing that one)

The video title “OpenStreetMap: The map that saves lives” suggests that this is all about humanitarian stuff, but if you watch the video, you’ll see we’re describing OpenStreetMap in general. OpenStreetMap and Humanitarian OpenStreetMap Team Together. Jonathan asked lots good general questions and seemed to understand some of the deeper issues and motivations of OpenStreetMap, and included this in the final cut. This makes a nice change. Over the years I’ve seen spikes of media interest (TV appearances and everything!) always about humanitarian OpenStreetMap, never so much about the bigger idea of making a free and open map of the world.

I’m also pleased that the video clearly shows how these stories flow into each-other nicely. It even ends with Ivan, a senior aid organisation figure, talking about the business impact of OpenStreetMap! And why not? It’s all the same story. It’s a brilliant story which we should all share in and be proud of together. OpenStreetMap old-timers should enjoy their part in the story of how we built a community and mapping platform which was capable of responding the way we did for Haiti, almost by accident. A spontaneous thing which later gave rise to HOT. We should also celebrate the fact that we are creating the very first maps of the developing world, and we are doing it as open data, starting these people’s maps off with a strong free & open footing, where otherwise the big G would probably conquer the territory first.

So this video popped up last week. And around about the same time recently, I published my talk, given at the Missing Maps meet-ups, about mapping your own neighbourhood.

Mapping Your Own Neighbourhood slide1

That’s a coincidence, but very much part of the same idea of stitching together the humanitarian mapping story with the overall OpenStreetMap story. Humanitarian mappers should look back at the history of OpenStreetMap and consider themselves part of this great endeavour to create a free map of the world (and make efforts to be a part of it more, by mapping your own neighbourhood)

But the timing of these is a fortunate too, because I see various folks recently creating/highlighting divisions between OpenStreetMap and the Humanitarian OpenStreetMap Team. Discussions around the orientation of OSMGeoWeek event listings, and the use of changeset comments coming from the OSM Tasking Manager, seemed to quickly illustrate that these communities have divided far more than necessary, and we really just need to talk to each-other more. Speaking as somebody who has always had a firm foot in both places, I find it frustrating that it’s not just a simple friendly collaboration. (This is before I even mention my despair at recent OSMF mailing list discussions)

But its OK because…

“Since giving this talk, everyone in the OpenStreetMap community is following my advice, and a new spirit of harmonious cooperation has settled over the project…” (echo from a 2009 blog post. Pigs might still fly). But seriously though. I know there’s real issues in these discussions. Issues we should work through. But they can get blown out of proportion. I hope this video and my talk are useful illustrations that OpenStreetMap and the Humanitarian OpenStreetMap Team are a friendly cooperative parts of the same whole. Let’s not be imagining otherwise. They are all part of the same brilliant story. I, for one, will continue to enjoy telling this story, every chance I get!

Hoxton, Brixton, and lots of data entry + Holborn tonight!

Posted by Harry Wood on 4 September 2014 in English (English). Last updated on 5 September 2014.

Last weekend I decided to ignore all my most pressing todo list items, chill out, and catch up on some mapping (Putting in map data based on all the photos I’ve collected) I’ve been getting behind on this, which gives me a familiar “really need to get around to doing that” feeling. That goes for everything on the todo list, but I allow mapping to jump to the top sometimes because the truth is, it’s nice and relaxing. I was in the mood for some long JOSM sessions last weekend so…

In went the data from the 14th May Baker Street mapping evening. Boom!. This was an event which I have actually already managed to write a diary entry about at least, but apologies to Marco, who may have been wondering why we didn’t seem to improve the map at all. Now we have (3 months later!)

In went my data from the 23rd June Hoxton Square mapping evening. Boom!. Actually other people had already got most of that data in, so I was just following up with A few additions and refinements around the square, and the block to the West of it.

This was the mapping evening featuring a radio reporter who followed us around and shoved a big microphone in our faces while we explained what we were doing.

The result of that was broadcast on an american radio station, and is also available to hear here: From Pen And Paper To 3-D, Look Who’s Challenging Google Maps. As often seems to be the case with these media appearances, it got very heavily edited down. I was cut completely. It just had a few phrases spoken by Robert, recorded while we were out mapping that evening. These soundbites and the commentary portray OpenStreetMap as rather a tin-pot project for crazy nutters, but… ah well… Any publicity is good publicity.

And we went to the Reliance pub in Shoreditch. This pub is an old favourite of my officemates at the Open Data Institute. That evening the world cup was on, and Brazil were still doing well (to flop out spectacularly in their next game)


In went the data from the 23rd Jun Brixton mapping evening. Boom!. This was a really nice sunny summer evening mapping session, so I got lots of photos of shops, and keying in all this data last weekend took me a long time. Quite interesting shops though, we were exploring the indoor markets and all the other dinky little afro-carribean/jamaican shops in the area. I’m sure there’s lots more shop mapping to do in the area though.


I enjoyed the sunshine. Along with photoing shops, I was trying to get some mapping action photos. I enjoyed having along Taichi who is one of the main OpenStreetMap community leaders in Japan, and Richard Pope who works for GDS and I’ve met at lots of hackathons (hope we can get him interested in OSM dev):

flickr flickr

And I enjoyed the burritos. Most of all I enjoyed leaving some things for somebody else to organise. Thanks Robert!

That was a lot of mapping data entry, but I still need to input some data from our recent Mayfair mapping evening. Still playing catch-up. Perhaps it’s a good thing then, that our next meet-up is just a nice relaxed pub meet-up. And when is this next meet-up happening? I shall tell you…


It 20 minutes the social OpenStreetMap drinking commences at the Penderel’s oak in Hoborn (details). Come join us!

Location: Brixton, Greater London, England, SW2 1SS, United Kingdom

OpenStreetMap birthday weekend (including wikimania etc)

Posted by Harry Wood on 20 August 2014 in English (English). Last updated on 31 August 2021.

Tonight we’re heading out mapping again! Join us for a London mapping evening in the Bond Street/Mayfair area.

I’m not doing very well at catching up with my diary entries on all the interesting things which have been happening. Since my last diary entry more things have happened, mostly all in one weekend! The weekend before last it was the OpenStreetMap 10th birthday party of course, but for me at least, that was not all:

  • Friday - Open Addresses Symposium
  • Friday night - wikimania entertainment
  • Saturday a.m. - wikimania OpenStreetMap sessions
  • Saturday midday - appearing on sky news
  • Saturday p.m. - OpenStreetMap birthday pub!
  • Sunday a.m. - breakfast with Frederik
  • Sunday - more wikiania sessions

The Open Addresses Symposium was an event put together by the Open Data Institute who have got funding to implement an Open Addresses project (dataset / software / community). In the UK we had an opportunity to make Royal Mail’s Postal Address File an open dataset (Why? Because it’s infrastructure. Make it free and open, and all kinds of innovation are quietly but obviously enabled) Instead our government recently sold it off as an asset along with the rest of Royal Mail, and this publicly-owned dataset was lost forever. Stupid. PAF was the topic of an open data campaign for years. It’s ended badly, but on the plus side it means we can write that off and move on. So at the Open Addresses Symposium, a couple of hundred address data experts and corporate users gathered to discuss this, and the idea of creating Open Address data. Steven Feldman has a write up here. The actual plan wasn’t laid out yet (discovery phase) but it will probably involve joining together various open data sets in clever ways, combined with some “crowd-sourcing” element.

Jerry and I were there representing OpenStreetMap. Being so busy lately I was grateful to not be doing a talk. Jerry did a great job of this:

on flickr

When it comes to OpenStreetMap there’s two big bits of bad news: (1) In the grand scheme of things we have data on only a tiny proportion of addresses in the UK (2) Our data has share-alike restrictions which this project would be aiming to avoid. But Jerry talked up the positives, and in particular the fact that OpenStreetMap community has a lot of experience (and open source code) in the “crowd-sourcing” side of things, on-the-ground surveying, and crazy JFDI approaches in general.

There was also a talk from the legendary Bob Barr. Always with an enjoyably passionate presentation style which gets the audience excited. I remember first seeing him give the opening talk at State Of the Map 2008, in which, coincidentally, he passionately argued for liberating address data sets!

Some good conversations with people in the pub afterwards too, but then I had to head off to…

Friday night - wikimania entertainment. I wanted to start taking in the buzz of wikimania. It is a buzzy kind of conference with a lively community, much like State Of The Map, only three or four times the size! Actually the buzz on Friday evening at the Barbican was a bit subdued. I suspect the real party was in a pub somewhere. I did however bump into some OSMers, Tim Waters, Edward Betts, and Paul the Archivist. There was a screening of the movie about Aaron Swartz which was inspiring, thought-provoking, and a bit depressing (available to watch on youtube there) Mostly it made me think “oh that’s what that SOPA thing was all about”. Maybe I should’ve paid more attention at the time.

Saturday a.m. - wikimania OpenStreetMap sesssions. Back to the wikimania venue the next day (which was looking a lot more lively) to catch the sessions about OpenStreetMap.

Andy Mabbett gave an introduction to OpenStreetMap for wikipedians. I realise I’ve probably now given more talks introducing OpenStreetMap, than I have seen other people’s talks doing so. It was interesting to see his way of explaining the project to a semi-technical audience. Very rich with examples of different map displays from Birmingham (and from the mappa mercia site), and “guess what this map is showing” audience participation. He also touched on some ways that we can look to link wikipedia articles to OpenStreetMap elements.

on flickr

Great to meet User:Seav. He’s setting up OpenStreetMap Philippines, but was over at the the wikimania conference and giving a talk about various collaborations between OpenStreetMap and Wikipedia. He went into some thorny license issues around (not) cross-sharing geo-data between the projects, which prompted some questions. I thought he did a great job answering all of these. It was one of those Q&A sessions where the audience is left in no doubt that the speaker really knows their stuff.

on flickr

After that Katie Filbert was running a HOT mapping workshop, apparently this went well but with some troubles due to poor wifi. I had to duck out just at the start of this unfortunately because I had to get to…

Appearing on sky news. This has to be one of the most bizarre experiences of my life. The day before I had a few emails and was suddenly lined up to be giving an interview about H.O.T. and our ebola response mapping. It seemed to be a live TV interview, but I wasn’t 100% sure until I got there. I headed over to the sky news studio at an address by the houses of parliament, which turned out to be a very grand old building entering via a cavernous wide stair-case. I saw an office full of desks and a big news studio type thing, but nobody around apart from one bloke who let me it. He was on the phone to their other studio and merrily led me past the office and into small dark cupboard. He sat me on a chair with TV camera pointing at me, and a small TV in the corner. His instructions were to “watch the monitor, then look at the camera”.

After a minute an ordinary newsreader woman appeared on the TV, except that she was picking her teeth and getting ready, which was a strange thing to see. Then suddenly, at 12:30 I suppose, she was reading the news headlines, and I was watching the very ordinary looking news as I relaxed sitting in my dark cupboard. Then she said “here with me now is Harry Wood from the Humanitarian OpenStreetMap Team” at which point I suddenly thought “ooh that’s me! look at the camera! look at the camera!”. I answered some questions about OpenStreetMap, and how MSF and Red Cross are using maps. Not sure if I got the key points across very well (fairly sure I didn’t in fact!). It felt like less than a minute and it was all done and dusted. Left the studio. Out into the sunshine.

I should’ve taken a photo of the news studio to prove I was there. Since then I haven’t been able to find an archive of the news online anywhere. One person on twitter said she’d seen it, but aside from that I have no evidence that my appearance on Sky News wasn’t just a weird daydream!

No time to ponder that though. I had to get back. I snapped this photo then got the tube back round to the barbican just in time to miss the end of the HOT mapping session! Worth getting back to appear in the wikimania group photo though. Also the OSMers at wikimania group photo:

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OpenStreetMap birthday pub! This was the main action of the weekend of course, although for me I was looking forward to chilling out with a beer after all the excitement. In the run up to this weekend I’d been bombarded with all sorts of the OpenStreetMappiness. I haven’t even had chance to mention how I was sent to Washington for H.O.T. the weekend before. Craziness! All of which meant I hadn’t had chance to do any spectacular preparation for the 10th OpenStreetMap birthday. Dan had a few ideas, and worked on putting out a press release (thanks!). When I sat down in the pub, I needed to finish writing a blog post!

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I was imagining I’d get time to do this before many other people arrived, but actually (despite me largely failing to promote the event properly) we had a lot of people coming along, and from quite early after the 3 o’clock drinking kick-off. Good show everybody! Also I was sad to have failed to organise any cake, but who needs to organise when we have a surprise distributed doacracy in action. Matt showed up with cake to make things OSMbirthdaytastic!

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Let’s just take a closer look at that.

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He was attempting to bake an OpenStreetMap logo through the middle of the cake! Looks a bit squashed, but it kind of worked. Good effort! Robert also got cake-creative. He was also worried we might not have a cake and so rapidly baked a parkin style cake with the Thames river icing sugar design sprinkled based on OSM map data of course.

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The choice of venue worked pretty well in the end. The Artillery Arms pub is pretty tiny, but as I had hoped, it was mostly empty at 3 on a Saturday, so we were able to rearrange tables and essentially take over half the pub. The take-over was complete when Dan wrote a birthday message on the blackboard behind us! And our numbers were swollen in the evening as people finished at wikimania nearby and popped over to join us.

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I should’ve got a better photo of the whole crowd, but I reckon we probably had 25 or 30 people there.

Of course… I was very drunk at time. Luckily Frederik was staying with me, so he could carry me home.

Frederik was also treated to some glorious english summer weather as we headed back to wikimania the next day. Despite having umbrellas, we got absolutely soaked on our lower legs. So yeah Sunday I was sat watching some wikimania talks with soggy trainers, feeling hungover. It reminded me of that time when I fell in the canal at SOTM Amsterdam… but that’s another story.

So yes. That was one hell of a weekend! But things are back to normal now. No cake at tonight’s pub (unless someone surprises me again!) but we do have a cake diagram! Edit that page to grab a slice of cake, if you want to help nail those Mayfair building outlines once and for all (is it ever going to happen?) Or just come to the pub from 8pm. All the details on the wiki for tonight’s event

[update: Just came across this nice write-up of the birthday pub by seav]

Location: Finsbury, London Borough of Islington, London, Islington, Greater London, England, N1, United Kingdom