Category Archives: OpenStreetMap

CLEANMAP

It wouldn’t be Rants & Renderings without the occasional OpenStreetMap post. The next few months mark the countdown to the switch to the Open Database Licence (ODbL)—as far as I know, come April, anyone who has not yet signed the new licence will have their work effectively removed from the OSM database. In some cases, these users’ accounts are simply no longer accessible but we still need them to accept the new terms in order to keep their edits.

I came across a neat site called CLEANMAP the other day. It’s basically a Mapnik rendering but with old licencees’ work removed. The site states that it “hide[s] objects that were created by mappers that have not [yet] agreed to the [new ODbL] contributor terms”.

Trumpington Road and Long Road missing, CleanMap

Annotated screenshot of southern Cambridge, as seen on CLEANMAP. Parts of the A1134 are missing on Trumpington Road and Long Road but most of the map will be preserved come the switch to ODbL. Not too sure what the licence of this image is anymore, so I'll assume it's copyright OpenStreetMap.org and its contributors / CC BY-SA.

My home town of Cambridge is alright for the most part: as annotated above, some parts of Trumpington Road and Long Road have gone missing but most of the city’s doing just fine. What would be more helpful is a rendering showing the inverse: ways and POIs that will disappear. And of course CLEANMAP only shows what Mapnik renders—as I’ve discussed on previous posts, Mapnik only renders certain ways, POIs and relations. The database goes far beyond roads, woodland and bus stops for example.

If anyone reading this hasn’t already agreed to the new terms, please consider. Read this guide as to why the change is taking place.

Transport Map

I haven’t blogged about OpenStreetMap recently. Since moving to the Netherlands, my contributions to the project have slowed right down and since the import of AND data in 2007 (which “finished off” 99% of the Netherlands), I seem to have lost my motivation for all but “armchair mapping“.

But that doesn’t mean I can’t continue to be a part of the project. The main reason I fell in love with OpenStreetMap wasn’t for its ‘default’ style (called Mapnik), but for what one could do with the data. The project and the maps it produces (or helps to produce) are based around a common tagging scheme. You’re perfectly welcome – encouraged even – to take the data and produce a map that shows only the ways, areas or relations with the tags you specify; and filter out or maybe colour differently other tagged data. Maybe that’s not a very good explanation but the idea is that your map or someone else’s specialist map doesn’t have to show the map features that aren’t relevant to its target audience or to its cause.

Here’s a better example. A new style (also known as a rendering) has recently been added to the “most popular” drop-down on the main OpenStreetMap website. Out of the hundreds of renderings out there on the Internet, only four have received the privilege of becoming featured layers on the OpenStreetMap website. The latest is called Transport Map and, as its name suggests, it highlights public transport routes and stops.

Public transport at London Stansted

The Stansted Airport area seen through Transport Map. Underlying data © OpenStreetMap.org and its contributors, CC BY-SA; tiles courtesy of Andy Allan.

Transport Map, as shown in the image of the Stansted Airport area above, shows quite clearly the area’s bus routes in red; and at high zoom levels, the line numbers of buses are printed along the route. The style also shows rail-based modes of transport as dashed black lines and as grey lines when underground (such as the tunnel under the runway at Stansted). You can also see the blue menu of the ‘promoted’ map styles at the top-left of the map in the screenshot above.

I really like the modern look of this particular style. The previous heavyweight in the public transport style arena was ÖPNV-Karte but I now find that style a little too …bulky. Do you remember when Apple changed the iTunes logo from thin green lines to thick blue ones?; I’m getting that feeling again. One can see a definite difference between the two maps’ designs if one compares them side-by-side.

Transport Map and ÖPNV-Karte

Central Amsterdam on Transport Map (left) and ÖPNV-Karte (right). Map data © OpenStreetMap.org and its contributors; CC BY-SA. Map tiles © their players.

In my opinion, the more recently designed Transport Map (left) is a lot less gunky and easier to read than ÖPNV-Karte (right). I’m a stickler for clean and minimalistic graphic design, and that’s what I think the Transport Map layer offers. It begins to get more convoluted at lower and lower zoom levels but that’s the case with all map styles.

But going back to talking about including or excluding certain tags from one’s custom style(s) for a second. Note how ferries are rendered in different ways in the screenshot of Amsterdam above. There are two ferries which cross the IJ from behind Centraal Station – ÖPNV-Karte renders ferries with relations purple (like the Fast Flying Ferry which heads northeast towards IJmuiden) but not the GVB ferries; Transport Map on the other hand recognises the tag route=ferry on ways as well as relations, since both companies’ ferries appear the same. All very boring stuff, but I hope it’s a good example of how different tags produce different results – there’s still plenty of work for “armchair mappers” like me to get on with.

OpenWhateverMap

I only discovered this today—OpenWhateverMap. OpenWhateverMap is basically an OpenStreetMap map, but each tile on-screen loads from a different tile server: one gets Mapnik, Osmarender, ÖPNV-Karte, OpenCycleMap, the Midnight Commander-looking one that I can’t remember the name of, etc., which makes OpenWhateverMap a little less useful (than just viewing one style) but it’s still neat to see what different how different renderers have developed to display information from the same OpenStreetMap database.

OpenWhateverMap: focusing on Hilversum, NL and my current place of work

OpenWhateverMap: focusing on Hilversum, NL and my current place of work. Licence: CC BY-SA 2.0

OpenWhateverMap also, if you look closely, includes tiles from Andy Allan’s OpenCycleMap’s new Transport layer (too many possessives?).

Lit ways, March–April 2011

I haven’t done an OpenStreetMap-related post for a while—so, as a token, I’m going to revisit the progress of the lit=yes tagging in the Cambridge region …something I covered in this post a few months ago.

Lit ways of southwestern Cambridge, March--April 2011. Rendering and data Creative Commons BY-SA 2.0 to OpenStreetMap.org and its contributors.

So what’s changed?; … not much, actually. The extent of Cambridge city’s lit ways is still very much limited to the southwest corner of town: Trumpington and Addenbrooke’s. The guided busway is partially lit, and the A1301 into Great Shelford forms the long ribbon of street lighting down to the bottom-right of the image above.

Street lighting isn’t too high up on the OpenStreetMap agenda: I’m assuming someone is to develop a fully-fledged OSM-based ‘sat nav’ and so I’m concentrating more on things like speed limits, number of lanes and road width—and also on tagging things which the CycleStreets engine picks up on: surfaces of cycleways and other highways in particular, which hopefully should be taken into consideration in a future version of the CycleStreets site.

Cambridgeshire and the humble FIXME

The tag fixme on OpenStreetMap is used to “mark objects […] that need further attention“. Using the XAPI, I’ve downloaded both nodes and ways within the bounding box -0.05, 52.03, 0.22, 52.25 which are tagged with the key fixme. When the two XML files are loaded into JOSM, they produce an unsightly picture of how much quality assurance work needs to be done. Below is an example of what I mean; the data being displayed in the screenshot is from 26th December 2010.

South Cambs fixme'd ways and nodes, 26th December 2010

Data copyright OpenStreetMap.org and her contributors; CC BY-SA 2.0

Busy-looking, eh? Just to bring this back to reality somewhat, here’s a similar screenshot with the outline of Cambridge superimposed:

fixmes, 2010-12-26 + outline of Cambridge

Data copyright OpenStreetMap.org and her contributors; CC BY-SA 2.0

If you are familiar with editing OpenStreetMap and live in the south Cambs area, this anchor will take you to Keep Right: an awesome “data consistency check[er]” for OpenStreetMap—just check the “fixme-tagged items” checkbox on the left. Each purple lightning bolt is a request for investigation.

Tagged

Three years

Today (11 December 2010) marks three years since I signed up for my OpenStreetMap account … according to my user page—and, in the years leading up to 3rd December (I’m writing this post early so I don’t forget this non-anniversary), I’ve submitted 1,989 changesets.

    Lit ways, November 2010

    The image below is how Cambridge and its southern surround looked from the air, at night, at the beginning of November 2010:

    Lit ways southwest of Cambridge

    Yellow highlighting for roads, et al. lit at night; dark yellow for unlit roads. Mapping data CC-BY-SA OpenStreetMap.org and its cronies; rendering published under an unknown licence, possibly CC BY-SA.

    It’s not exactly the best rendering ever, but this is the thing: if this lit=* map was (let’s say) the fourth layer on the OpenStreetMap website (along with Mapnik, Osmarender and OpenCycleMap), coverage of lit and unlit ways would be different. People tag information they know will get rendered; maybe it’s a “here’s some visual/cartographical proof of what I’ve done]” thing. OpenCycleMap is a good example of this rendering-uptake effect: people heard about and went to see OCyM, people went and surveyed national and regional cycle routes, the routes got rendered, people went to see OCyM, … I could insert a weak cycle/(bi)cycle joke here but I won’t; it’s a cycle. You get the gist of what I’m trying to say …right?

    Coverage of lit=* is not great in the East of England but I do enjoy night cycling and going for walks at night, though the latter option doesn’t exactly get me very far from home; hopefully by combining night cycling and remembering to take my Garmin out on rides, I can improve the coverage somewhat. So that would be bus routes, farmland and street-lighting; you’re welcome, OpenStreetMap.

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