Category: Data Graphics

The Open Knowledge Foundation (OKFN) have produced a census for government open data availability for countries around the world, known as the Open Data Index. Each country is assigned scores for 10 attributes on openness and accessibility for each of 10 types of data (such as election results and pollution information). Currently the United Kingdom is at the top of the table.

More recently, OKFN expanded the concept to look at open data for cities within each country, in other words data that is managed at the City Hall level. For example, there is a project page for individual cities within the UK. This time, 15 types of data are examined, again each gaining up to 10 points for openness. The project is still in its information gathering stage so, at the time of writing, only 6 cities have their data partially, or fully, entered. The census for Italian cities, for example, is looking more complete.

Such a census is of great interest when building an application like CityDashboard, which is currently available for eight cities around the UK. Although CityDashboard doesn’t only use open data sources, those which do have documented APIs, open data licences and machine readable formats greatly aid building and expanding a website such as CityDashboard. CityDashboard takes in social media and sensor data, as well as “official” data of the sort that is being categorised by the OKFN project, but some data, such as live running information for metro services, will quite likely always best come from the official sources.

As such, I will keep a close eye on this project. Cambridge and Sheffield look like two promising cities for which the necessary official data is both available and open, which would make implementing them in CityDashboard relatively straightforward.

The census is user-driven and reviewed, so it’s up to you to get information on the availability (or lack) of data for your local city catalogued in the census.

Since launching the data store in early 2010, the Ordnance Survey have been releasing a number of updates to an interesting dataset – VectorMap District – which is a generalisation and simplification of their MasterMap “gold standard” dataset for Great Britain. The updates have been appearing roughly every 6-12 months, and by comparing them in a GIS, you can start to see how places change – at least in the eyes of the Ordnance Survey surveyors tasked to keep the map current. Roads occasionally get built, but building footprints evolve more rapidly – as office blocks and housing developments get taken down and rebuilt with higher capacities or more glass windows.

I’ve taken three of the VectorMap District dataset releases – April 2012, September 2013 and March 2014 – combined the data together and used QGIS’s layer compositing operations to show the geographical differences.

The colours tell of the age of the building – bearing in mind that there is a lag of a few months or years between buildings appearing/disappearing in real life, and on the map. For example, the Olympic Stadium, the turquoise oval above, appears in the 2013 dataset but not the 2012 one, even though of course it was finished in 2011, for the London 2012 Olympic Games.

Above, much of the Olympic Park can be seen – the permanent new buildings (turquoise), temporary buildings for the Games only (blue) and demolished for the games and associated planned development (red). Below, the map covering a wider part of London, zones of activity can be seen. For example, demolition associated with the Nine Elms and Deptford Creek developments (red), and major new blocks such as near the Arsenel stadium (yellow).

Important Note

Between the 2012 and 2013 datasets, the Ordnance Survey changed they way they applied the generalisation on the data, so some of the 2012-2013 changes (shown as red on the maps here for reductions, and turquoise for additions) are as a result of this. For example, narrow gaps between buildings, that always existed, are shown for the first time in 2013 in red (building reductions).

As such, my map slightly overemphasises changes between 2012 and 2013. For example, the pitch at Arsenal and the Great Court at the British Museum appear as changes, but they were always there. As a rough rule of thumb, the smaller red/turquoise patches are due to the generalisation changes, the larger areas of colour show genuine change. With this important caveat, the map remains an interesting insight into London changes, and the larger coloured regions give a good indication of parts of London which are undergoing intensive building redevelopment.

The Bigger Picture

Here is the map for central London – click on it to see a full-size version.

[Buy this print!]

London North/South shows every building block in central and inner city London, coloured blue if it’s north of the River Thames and red if it’s south. And that’s all. No other features are shown, and yet, from this simple premise, a map of the city appears. Almost every street is visible, as a linear white line. Longer lines, with gentler curves, particularly in south London, are often the railways. Stadia are noticeable for generally having a football-field-sized hole surrounded by an often oval block of colour. St Paul’s Cathedral is surprisingly small, but obvious if you know where to look. Big holes in the map are London’s grand parks – Hyde Park and Kensington Gardens being perhaps the most distinctive, as they are surrounded on all sides by densely packed building blocks. A flash of blue appears in the bottom left corner of the map – a mistake? No, the Thames wiggles so much in west London, that this area (Hampton Wick), on the far south of the map, is in fact on the river’s north bank.

The map has 48912 shapes on it – 28200 in blue and 20712 in red. It covers, I think, more than half of London’s eight million plus population, suggesting an average of around 100 people live in each housing block. It does include industrial and commercial buildings, but it’s a fair assumption I think to say that the great majority of buildings in London are residential ones.

The map is centred on a spot just south of Waterloo Railway Station, which is the geographical centroid of Greater London – despite this being south of the river, while the major institutions of the capital – and most of Zone 1 of the tube network – are on the north.

One feature which is on almost all London maps is the River Thames. Famously, when it was removed from the official tube map a few years ago, there was a big outcry and it was hastily restored. This map doesn’t have the Thames on it – but the space through where it runs is obvious. Think of it as being there after all – but coloured white.

I’ve had the graphic professionally litho-printed and it is currently available as a limited edition A2 edge-to-edge print which you can buy from my new online shop, as one of two designs available at the shop’s launch. So far, it’s comfortably outselling the other print which is an update of my Electric Tube design. I think a lot of people like the idea of owning something which has their house on it!

The data comes is Ordnance Survey’s Vector Map District, released under the Open Government Licence. The data is therefore Crown copyright and database right Ordnance Survey 2014. It was prepared in QGIS 2.0, with finishing touches and colouring carried out in Illustrator.

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A couple of years I drew a quirky tube map to commemorate the completing of the circle on London’s Overground, affectionally known as the Ginger Line. The artwork has proven to be quite popular so I’ve produced a print run of an updated version of it. The new version retains the circles, loops and quirks of the original, but I took the opportunity to fix a few lines that weren’t quite right, and throw in a few more wiggles – have a look at that DLR!

Here’s what I wrote previously:

My starting principles for the diagram were concentric circles for the orbital sections of the Circle Line and the Overground network, and straight lines for the Central and Piccadilly Lines, with the latter two converging in the centre of the circles. I then squeezed everything else in. I realised that the Northern Line’s Bank branch passed the Circle Line three times so was going to need something special, so I added a sine wave for this section, and extended this north and south as much as possible.

The River Thames is on there – because any tube diagram doesn’t look correct without the river – and the diagram is topologically accurate – everything connects correctly, and features are in an approximately correct geographical position relative to their neighbours, but not to the diagram overall. Only stations that are designated intersections, or have connections with National Rail stations, are shown. I haven’t labelled anything. It’s art.

I was also thinking about physics when creating the diagram – specifically Feynman diagrams, bubble chamber traces, particle physics collisions, magnetic flow lines and electrical circuit diagrams (as was Beck himself). Hence why I’ve called it the Electric Tube.

The work was also inspired by the likes of Fransicso Dans (more) and Project Mapping, as well as of course the famous Official Tube Map.

The limited edition prints can be bought from my online shop.

The charity auction for the artwork/map that I created with Dr James Cheshire, Data Windows, took place last night, at the Granary Building in King’s Cross. Our work was part of the silent auction section and received four bids, going eventually for £140. James and I are delighted that our map sold, and contributed to the fundraising effort.

Having looked at the other artworks that were on display, I was a little worried ours wouldn’t sell at all. There were many very impressive works, many that went for well above my budget, including a few for over £1000. The pieces by Dame Zaha Hahid and Lord Richard Rogers went for over £2000. The theme this year was drawing the area around Shoreditch, and the Hawksmoor-designed church of Christchurch Spitalfields appeared numerous times. My personal favourite work was Cycledelious, which was a bright multicolour stylised drawing of a Barclays Cycle Hire docking station. However it approached £200 before I had even got to it to put a bid down. The organisers’ strategy of very regularly topping up our wine glasses meant that I did very nearly end up bidding on several items…

You can find out more about how Data Windows was made in this earlier post.

Photo courtesy of Isla.

The London Cycling Census Map is an interactive map I’ve created, showing traffic flows on key corridors in central London. The counts were collected by Transport for London in around 170 locations, in April. TfL released some sample statistics from the dataset in a report published on their website, but the original dataset was not released – however Andrew Gilligan, the Greater London Authority’s cycling commissioner, obtained the data and forward it on to a number of people, including (indirectly) me. I took the data, consolidated it, and created this map. The most tedious bit was pointing the arrows in the right direction!

There are three time periods for which you can show data: AM Peak (7am to 10am), PM Peak (4pm to 7pm) and All Day (which is, I believe, a 24-hour sample.) which is from 6am to 8pm. The locations chosen are generally ones where high numbers of cyclists travel, so some roads which have high numbers of other vehicles, but not bicycles, e.g. Oxford Street, are not included.

Cycling along key corridors in London is highly time dependent – in the below extract, morning (red) and evening (green) flows for cyclists are compared. Cyclists generally travel away from Clerkenwell, to the east and the west, in the morning, returning to it in the evening. The other travel modes generally don’t show this directionality on this road – cars in particular generally travel in both directions during both peaks. I would hypothesis that the cyclists are accessing this road from Goswell Road, which unfortunately wasn’t included in the census.

So what does the data show?

• There are several roads where there are more bikes on the streets than any other type of vehicles.
• Bicycle flow is highly direction, unlike that for most other forms of transport.
• There are certain routes which are popular with certain kinds of traffic. There are four main east/west corridors in central London. Cars dominate the north-most (Euston Road) and the south-most (Victoria Embankment) ones. Taxis heavily use Holborn, while cyclists mainly use Old Street/Theobald’s Road. You can see all four of these corridors in the map extract at the top of this article.
• Equivalent north-south links show little separation of vehicle types.
• Elephant & Castle remains a complicated junction with large numbers of cyclists and buses, depending on the direction, road and time of day.

A note on the arrows

The map uses the vector styling capabilities of OpenLayers, with a custom SVG “arrow” symbol. Symbols in OpenLayers are always positioned with their centre over the location point, so to have them pointing away from the location, I had to add a hidden stalk to each arrow – you can see the stalk when clicking on it. My custom SVG for the arrows is:


OpenLayers.Renderer.symbol.arrow = [1, 0, 0, -3, -1, 0, 0, -0.5, 0, 3, 0, -0.5];


I’m using 0, 0 as the point on the arrow that corresponds to the underlying location – but it doesn’t need to be that, i.e. the location of 0, 0 does not affect where OpenLayer actually pins your symbol on your point location.

And finally…

Red arrows are taxis, blue arrows are buses. Proof, perhaps, of the oft-quoted saying that it’s a battle to find a London taxi driver willing to go south of the river:

The map was created as an output of EUNOIA, a European Union funded project to model travel mobility in major European cities using novel datasets. UCL CASA is the UK university partner for the project.

You can view the map here.
View alternative version of the map – uses OpenCycleMap as a basemap.
Download the data here which I have augmented with bearings.