Recent diary entries
I'm at the OpenStreetMap Hack Weekend March 2014. Things done:
One of the things I'm really happy about is that Richard Fairhurst's addition of routing to the OpenStreetMap main website is really close to being ready - just a couple of tiny bugs and UI bits to iron out, and who knows, maybe it'll go live soon. I helped with a couple of little improvements and fixes.
The other thing is a conversation with new mapper Micky Allen, who is interested in mapping blue badge parking spaces. It turns out that in OSM we have a handy tag capacity:disabled=*, which is already used quite well in London, but we just need a bit more community effort to map these "blue badge" parking bays whenever we see them. Micky now has some ideas about how to extract these data from OSM, and he also has some ideas about encouraging the community to join in mapping them. I'll certainly try and remember to map them when I see them.
Next thing we've done this afternoon - some improvements to v2 of the HOT Tasking Manager. I've made it auto-unlock locked tasks after time (feature migrated from v1) as well as a couple of smaller tweaks.
Over on my blog I've put an article in which I attempt to reconstruct the surface terrain of the UK from OSM "ele" data. The results look like this:
As a contributor to OpenStreetMap, one thing I've been wondering recently is what sort of map data should we collect for the UK, now that the coverage has already got good. Since OpenStreetMap generally has great coverage of the UK, when you're out and about with a printed-out map and a pen, it's very rare that you can find much significant that isn't mapped already - sometimes a new street or a missing church. You could pour your time into mapping increasingly obscure things, whatever you're interested in. But what would be the most useful things to map in the UK, over the coming year? Things that are not just interesting to map but could be practically useful to people? Some thoughts:
- Addresses. I kind of don't like mentioning this, because I find it boring to map addresses, and I'd much rather that the UK address data magically appeared from some big open-data source. But addresses are obviously really useful for so many things: routing, looking up shops, etc. Coincidentally, Simon Poole (chair of OSM Foundation) also says address collection is the thing we need, for OSM in general not just UK.
- Postcodes. In the UK postcodes are really important for satnav routing etc. For some reason I suspect that collecting postcodes could be less mind-numbing as collecting addresses, but just as useful. See Jerry's blog about UK postcodes in OSM for an analysis of where we are with postcodes... about 3% of them. As he says, we need to do better than this - so how best to collect them?
- Footpaths. Really important for planning walking routes, whether in the city or the countryside. We also need to mark when footpaths have steps or are otherwise no good for wheelchairs/prams. (It's also handy to know when footpaths are full-blown rights of way, or just "permissive" access.) In his speech at State Of The Map 2013, Peter Eastern mentioned that they estimated UK footpath data was still pretty incomplete. I often use OSM for planning walking routes - it has loads of footpaths that no other services have, but I do still often go walking somewhere and find new footpaths that aren't in there yet. I don't know how we could specifically push for more footpath mapping - all I will say is please help us and map walking routes :)
Some notes on other things which I'm not sure how vital they are:
- Buildings. I know when we've been doing London mapping meet-ups, Harry Wood has mentioned that OSM's buildings coverage for London is rather patchy. You can see it on the map - there are pockets full of buildings mapped, and large pockets with none. But... is this a bad thing? What would we want buildings mapped for? I know they're useful in fancy 3D map renderings, but for more practical purposes...? I'm guessing it's not that crucial, though it might relate a bit to the address mapping.
- Shops. It's great to have shops, restaurants, pubs and other local businesses in OSM. Once you start mapping these, though, you notice there's quite a rapid turnover - your high street probably gains/loses a shop every 3 months or so, at a wild guess. So this data is useful, but it's less permanent than all the other stuff I've mentioned so far. I'd suggest there's no point having a big push to map every shop in every high street, we just need to let the momentum build to a point where that happens under its own steam.
- Postboxes. Again Jerry has a detailed breakdown, and says we need to map them more. Plus Robert Whittaker has some data mining tools about postbox completeness. On the other hand, is it really that urgent to map postboxes? It doesn't feel anywhere near as critical as mapping addresses, walking routes, etc. The only use case I can think of is "where's the nearest postbox?" which is rarely a critical matter.
- GPX traces. After MapBox published their beautiful rainbow GPS map tiles which provide a lovely way to see the GPS traces contributed by the community, I noticed at least two villages where there were basically zero traces uploaded. Are GPS traces important to UK mapping? The coverage of the aerial imagery is good, and generally quite well GPS-aligned, so... do we need more GPS traces around the UK? I genuinely don't know, and would be interested to find out either way.
- Grit bins. Something I noticed a couple of winters ago - it would be really handy to have every grit bin mapped: one day, when it's freezing cold outside, all the grit bins are hidden under a foot of snow, and you need to clear a driveway, it could be really handy. That's just one little thing that I don't think anyone has particularly focussed on, so a little call out - please map amenity=grit_bin when you see them!
I'd be grateful for any feedback on the thoughts above, including other things that could be priorities. Just one UK mapper's perspective.
I don't think I used to map post-boxes. Partly because I'm not that interested in them, partly because I sort of assumed they should have been imported en masse at some point from a Royal Mail open data dump of some sort (naive?).
But when I read SK53's interesting post about the completeness of post-box mapping in Britain, I was really surprised to learn that OSM had less than 50% of the postboxes in Britain. So I've started mapping post boxes when I come across them.
As it turns out, I could have started with the one at the end of my road. It was already there in the map, but it had the wrong reference number, though I only noticed that recently. Even in central London and central Birmingham (two hyper-mapped cities) I've found some postboxes that have sat there unmapped for years.
Anyway, a quick search finds that I've added or fixed 79 post-boxes in the map so far. Mappers, next time you see a post-box, please map it - post boxes are useful things to have on a map...
One of the great things about editing OpenStreetMap is that it leads me to discover new bits of my local area. I've just come back from a lovely walk in North-East London, a walk which I would have never thought of doing if it hadn't been for OSM. And what's more, it led me to discover a really lovely seafood place for lunch!
Here's how I do it:
- When it's a nice day and I fancy a walk, I go and look at ITO's FIXME map, which simply highlights all the objects in the map with "fixme" tags. Most of the time the issues described in the tags are things that can be fixed if someone goes to survey the place (e.g. "check name", "does this footpath really exist"). I pick a few of these fixmes, not too far from home, as waypoints for my walk.
- I usually also go to walking-papers and print myself a simple walking map of the area. I note on this map, the things I need to check.
- Then I go and walk. These days I usually record the GPS trace of my route using my Android phone (I use the "OSMTracker" app) - it's handy but not necessary; just walking around with the piece of paper is fine. For some purposes I prefer scribbling on paper, while sometimes it's quite handy to store notes in the phone.
- When I come back, I upload the GPS trace and use my notes to update the map, fixing things and removing the "fixme" tag wherever I've actually fixed something. The aerial photos that OSM offers (via Bing etc) help to jog your memory as you edit, and often prompt me to add features that I didn't explicitly note down while I was walking.
Really the best thing about this is that while I'm directly fixing things that people want fixing, I'm also discovering bits of my local area that I had no idea about. There was one walk where I discovered an entire park in North-East London that I had never heard of before (and wasn't properly mapped yet, either).
The highlight of today was that my route led me past a fantastic seafood place, and just in time for lunch as well!
On OpenStreetMap, I find the /browse/ pages really useful for getting a quick summary of an "object" in the map. It shows when it was edited, shows all the tags, etc.
However, I have two issues with it:
- The use of space isn't ideal. There's plenty of unused space which I don't think is entirely deliberate (of course whitespace is good sometimes) - and the interesting information often gets pushed down below the fold as a result.
- The browse pages have enough information that they should be generally useful, not just as a diagnostic tool for mappers, but maybe for people who want to share the details of the pub they're going to, or whatever. The main impediment to this is that the initial impact of the page is fairly unfriendly and technical.
I believe the layout can be rearranged in a way which doesn't remove any of the information that mappers need, but which makes the browse pages more accessible and friendly and hopefully generally useful. This would encourage more casual users to see the tags we have, and... fix them :)
So the main objectives are:
- Make the main heading a bit more approachable, making the "name" (where available) a bit more primary than it currently is.
- Make the "Tags" section a little bit more visually primary (more approachable to newcomers than changeset).
- Make the "last edited" info more compact - it doesn't need to be a four-row tabulation, but can be as a sentence "Last edited [date] by [user], (version [v] in changeset [c])". It makes sense to put the "View history" link at the end of this too. Also, it's more approachable to have the last-edited-date converted to something like "2 months ago", and for full info it'd be good to have the full date tooltippy.
- Try not to do anything that prevents experienced mappers from getting a visual overview of the more technical info, such as history, XML link, edit links etc.
Work so far is in my github branch called "browsepage".
I've written a bit more on my own blog including screenshots.
I really think the "Last edited N decades ago by Thor" is much more approachable than the current table of metadata. The other stuff I've done is less dramatic, but I like the way it gives a bit more priority to the tags and makes room for plenty of them in a screenful.
On my blog I made some notes about Diversity and OpenStreetMap, inspired by some of the really interesting talks at SOTM.
This weekend I've been doing some "humanitarian" aerial mapping in response to the floods in North India. My first time trying to map a country I've never visited, where the map might be used for immediate important purposes. I must say it's a bit nerve-wracking, for those exact reasons:
- Firstly I've never been there and I'm not that familiar with the mountainous terrain. Sometimes it's easy to be tracing a river and then you realise you're actually tracing a road after all. When you're not familiar with it, it's much easier to get confused when tracing aerial imagery. We're lucky that the bing aerial coverage for this area seems to be good high-resolution stuff.
- Secondly the mapping might turn out to be important. So, what if my amateurish edits lack something that would have been filled in by another mapper, if only I hadn't filled the map up with simple-minded route-tracing (eg with no idea of which roads are major/minor)? What if I'm tracing a road from an old aerial photo, when locals would know that the road isn't there any more? What if I'm not tracing the things that would be important for humanitarian relief purposes? What if I'm accidentally joining up roads that don't join? etc etc etc. Harry Wood's 2011 discussion of "blooms and weeds" in mapping summarises some ideas about whether importing low-quality data into OSM has a retarding effect on the map's subsequent growth. Maybe rushed naive armchair mapping has a similar effect...
The Humanitarian OpenStreetMap Team ("HOT") has evolved a way of doing things, and I've been a little bit surprised that it's tricky to know how to get involved. By the time a "task" is established in their "tasking manager", it often seems that the basic, low-hanging-fruit stuff like tracing major roads is already done. On the other hand it's good that that stuff gets done quickly because it's presumably important info. This time (with the case of India) I've been able to do some fairly comfortable tracing of roads and rivers, which is good for my own participation. On the other hand it may suggest there's a lot of mapping of the area yet to do, before it becomes useful!
Another iteration of my visualisation of OpenStreetMap edits - here's an animation showing, for each year 2005-2012, the density of edits according to their geographic location:
The upper plot is the raw edit density. The lower one (which I think is more illuminating) is the edit density per unit population, as described in a previous post (with source code).
So what can you see? Well, both of them show the humble London-centred beginnings in 2005, followed by solid growth until the whole world is filled out. I think the lower plot more clearly shows when the "filling out" happens. 2007 is the year OpenStreetMap "goes global" but 2009 is the year it levels out. Before 2009, the edits-per-population are very variable, but from 2009 onwards the picture is much whiter and there's not much annual change in the colouring. This means the distribution of edits much more closely fits the population distribution, though (as noted last time) central Africa and around China are relatively underrepresented.
(This is cross-posted from my blog)
Here's a data-driven way to decide where the next OpenStreetMap recruitment drive should be. Take the geographical spread of edits in 2012, and divide it by the geographical spread of the population, to see where there are most/least edits "per person":
More details on my blog article about it.
OK, if you want to know where in the country has good pubs, how do you do it? Well, here's what I do: download a data extract of all the pubs in the UK/Eire from OpenStreetMap, and use density estimation to look at the distribution of pub attributes such as whether it serves real ale, or food, or has wifi. That's the normal way, right?
In my blog article about pubs in UK & Eire I've posted more plots, as well as the source code and some extra info.