Category Archives: London

Lives on the Line v2: Estimated Life Expectancy by Small Areas

livesontheline_district

I’ve produced an updated version of a graphic that my colleague Dr James Cheshire created a few years ago, showing how the estimated life expectancy at birth varies throughout the capital, using a geographical tube map to illustrate sometimes dramatic change in a short distance.

You can see an interactive version on my tube data visualisation platform. Click a line colour in the key on the bottom right, to show just that line. For example, here’s the Central line in west London.

The data source is this ONS report from 2015 which reports averages by MSOA (typical population 8000) for 2009-2013. I’ve averaged the male and female estimates, and included all MSOAs which touch or are within a 200m radius buffer surrounding the centroid of each tube, DLR and London Overground station and London Tram stops. I’ve also included Crossrail which opens fully in 2019. The technique is similar to James’s, he wrote up how he did it in this blogpost. I used QGIS to perform the spatial analysis. The file with my calculated numbers by station is here and I’m planning on placing the updated code on GitHub soon.

livesontheline_alllondon

My version uses different aggregation units (MSOAs) to James’s original (which used wards). As such, due to differing wards and MSOAs being included within each station’s buffer area, you cannot directly compare the numbers between the two graphics. An addition is that I can include stations beyond the London boundary, as James’s original dataset was a special dataset covering the GLA area only, while my dataset covers the whole of England. The advantage of utilising my data-driven platform means that I can easily update the numbers, as and when new estimates are published by the ONS.

Estimating life expectancies at birth for small areas, such as MSOAs, is a tricky business and highly susceptible to change, particularly due London’s high rates of internal migration and environmental change. Nevertheless it provides a good snapshot of a divided city.

View the interactive version.

livesontheline_dlr

Data: ONS. Code: Oliver O’Brien. Background mapping: HERE Maps.

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High quality lithographic prints of London data, designed by Oliver O'Brien

Smart Mobility Meeting in Mexico City

Below is a presentation that combined my talks last Thursday and Friday at the Smart Mobility forums in central Mexico City, organised by ITDP Mexico and funded by the Foreign and Commonwealth Office’s Prosperity Fund (respresented by the British Embassy in Mexico). The Thursday presentation focused on the third-party app ecosystem that exists around bikesharing in London and elsewhere, while the Friday presentation included more examples of private sector innovation using open data:

My week in Mexico City also included a visit to CIC at IPN (the computational research centre city’s main polytechnic) where I was introduced to a product building visualisations of ECO-BICI data to help create more effective strategies for redistribution. I also visited LabCDMX, a research group and ideas hub to study Mexico City that has been created by the city government, to give a couple of talks in their rooftop on visualising London transit and a summary of web mapping technologies. The organisers also squeezed in a couple of short TV interviews, including Milenio Noticias (23 minutes in). The week ended with a tour of the ECO-BICI operations, repair, management and redistribution warehouse, located centrally and a hive of activity. This included a look at their big-screen redistribution map and vehicle routing system.

Some of the companies and products I cited included CityBikes, Cycle Hire Widget, TransitScreen, ITO World, Shoothill, Waze, Strava Metro and CityMapper. I also showed some academic work from myself, James Cheshire and Steve James Gray in UCL GSAC and UCL CASA respectively, an article in The Guardian by Charles Arthur, an artwork by Keiichi Matsudaa and a book by James Cheshire and Oliver Uberti. I also mentioned WhatDoTheyKnow and heavily featured the open data from Transport for London.

I also featured some work of my own, including CDRC Maps, TubeHeartbeat, London Panopticon, Tube Stats Map, CityDashboard, Bike Share Map and London Cycling Census map.

ecobici

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Big Data Here: The Code

So Big Data Here, a little pop-up exhibition of hyperlocal data, has just closed, having run continuously from Tuesday evening to this morning, as part of Big Data Week. We had many people peering through the windows of the characterful North Lodge building beside UCL’s main entrance on Gower Street, particularly during the evening rush hour, when the main projection was obvious through the windows in the dark, and some interested visitors were also able to come inside the room itself and take a closer look during our open sessions on Wednesday, Thursday and Friday afternoons.

Thanks to the Centre for Advanced Spatial Analysis (CASA) for loaning the special floor-mounted projector and the iPad Wall, the Consumer Data Research Centre (CDRC) for arranging for the exhibition with UCL Events, Steven Gray for helping with the configuration and setup of the iPad Wall, Bala Soundararaj for creating visuals of footfall data for 4 of the 12 iPad Wall panels, Jeff for logistics help, Navta for publicity and Wen, Tian, Roberto, Bala and Sarah for helping with the open sessions and logistics.

The exhibition website is here.

I created three custom local data visualisations for the big screen that was the main exhibit in the pop-up. Each of these was shown for around 24 hours, but you can relive the experience on the comfort of your own computer:

bdh_buses

1. Arrival Board

View / Code

This was shown from Tuesday until Wednesday evening, and consisted of a live souped-up “countdown” board for the bus stop outside, alongside one for Euston Square tube station just up the road. Both bus stops and tube stations in London have predicted arrival information supplied by TfL through a “push” API. My code was based on a nice bit of sample code from GitHub, created by one of TfL’s developers. You can see the Arrival Board here or Download the code on Github. This is a slightly enhanced version that includes additional information (e.g. bus registration numbers) that I had to hide due to space constraints, during the exhibition.

Customisation: Note that you need to specify a Naptan ID on the URL to show your bus stop or tube station of choice. To find it out, go here, click “Buses” or “Tube…”, then select your route/line, then the stop/station. Once you are viewing the individual stop page, note the Naptan ID forms part of the URL – copy it and paste it into the Arrival Board URL. For example, the Naptan ID for this page is 940GZZLUBSC, so your Arrival Baord URL needs to be this.

bdh_traffic2

2. Traffic Cameras

View / Code

This was shown from Wednesday evening until Friday morning, and consisted of a looping video feed from the TfL traffic camera positioned right outside the North Lodge. The feed is a 10 second loop and is updated every five minutes. The exhibition version then had 12 other feeds, surrounding the main one and representing the nearest camera in each direction. The code is a slightly modified version of the London Panopticon which you can also get the code for on Github.

Customisation: You can specify a custom location by adding ?lat=X&lon=Y to the URL, using decimal coordinates – find these out from OpenStreetMap. (N.B. TfL has recently changed the way it makes available the list of traffic cameras, so the list used by London Panopticon may not be completely up-to-date.)

bdh_census

3. Census Numbers

View / Code

Finally, the screen showed randomly chosen statistical numbers, for the local Bloomsbury ward that UCL is in, from the 2011 Census. Again, you can see it in action here (wait 10 seconds for each change, or refresh), and download the code from GitHub.

Customisation: This one needs a file for each area it is used in and unfortunately I have, for now, only produced one for Bloomsbury. The data originally came, via the NOMIS download service, from the Office for National Statistics and is Crown Copyright.

bdh_traffic3

Big Data Here

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The Consumer Data Research Centre (CDRC) at UCL is organising a short pop-up exhibition on hyperlocal data: Big Data Here. The exhibition is taking place in North Lodge, the small building right beside UCL’s main entrance. The exhibition materials are supplied by the Centre for Advanced Spatial Analysis (CASA).

Inside, a big projection shows local digital information. What the screen shows will change daily between now and Friday, when the exhibition closes. Today it is showing a live to-the-second feed of bus arrivals at the bus stop outside the North Lodge, and tube train arrivals at Euston Square station just up the road. Watch the buses zip by as they flash up “Due” in big letters on the feed. Both of these are powered by Transport for London’s Unified Push API, and we are planning on publishing the visualisation online next week. Tomorrow will be showing a different local data feed, and then a final one on Friday.

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Opposite the projection is the iPad Wall. This was created by CASA a few years back by mounting a bank of iPads to a solid panel (above photo shows them in test mode) and allowing remote configuration and display. The wall has been adapted to show a number of metrics across its 12 panels. Four of these showcase footfall data collected by one of our data partners, and being used currently in CDRC Ph.D. research. The other panels show a mixture of air quality/pollutant measures, tube train numbers and trends, and traffic camera videos.

We hope that passersby will enjoy the exhibition visuals and use them to connect the real world with the digital space, a transposition of a digital data view onto the physical street space outside.

The exhibition runs 24 hours a day until Friday evening, with the doors open from noon until 3:30pm each day. The rest of the time, the visualisations will be visible through the North Lodge’s four windows. The exhibition is best viewed at night, where the data shines out of the window, spilling out onto the pavement and public space beyond:

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Big Data Here is taking place during Big Data Week 2016. Visit the exhibition website or just pop by UCL before Friday evening.

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Busiest Tube Station Times

chesham_max

Here are the busiest Tube station quarter-hour periods, based on the Transport for London 2015 RODS data (modelled, based on typical autumn weekday), used in Tube Heartbeat, adding together entries, exits and interchange stats and excluding Kensington Olympia which does not have a frequent Tube service.

The main pattern shows that stations further out (map) from London’s main work areas (The West End, the City and Canary Wharf) have an earlier morning peak (or later evening peak), due to the journey taking longer and the tendency for many people to arrive at their work-end station at about the same time – just before 9am. A secondary effect is that stations which just act as simple commuter home and work portals, we would expect the usage to peak in the morning rush hour, rather than than evening one, as the morning rush hour is shorter and so the simple commuter flow is more concentrated. Therefore, stations which show a peak in the evening are often due to a combination of this simple commuter flow and an evening “going out” destination.

Station Peaks by Time of Day

7:15am-7:30am: Chesham [Zone 9]

7:30am-7:45am: Chalfont & Latimer [8], Epping [6]

7:45am-8:00am: Amersham [9], Chorleywood [7], Debden [6], Elm Park [6], Hillingdon [6], Hornchurch [6], Theydon Bois [6], Cockfosters [5], Pinner [5], South Ruislip [5], Stanmore [5], Mill Hill East [4], Chigwell [4], Grange Hill [4], Perivale [4],Kew Gardens [3/4], Wimbledon Park [3], Holland Park [2]

8:00am-8:15am: Alperton, Arnos Grove, Balham, Barking, Barkingside, Becontree, Buckhurst Hill, Canons Park, Chiswick Park, Clapham South, Colindale, Colliers Wood, Croxley, Dagenham East, Dagenham Heathway, Eastcote, East Putney, Edgware, Fairlop, Finchley Central, Gants Hill, Hainault, Harlesden, Harrow-on-the-Hill, Hatton Cross, High Barnet, Hounslow Central, Hounslow East, Hounslow West, Ickenham, Kenton, Kingsbury, Loughton, Moor Park, Morden, Neasden, Newbury Park, Northfields, North Harrow, Northolt, Northwick Park, Northwood, Northwood Hills, Oakwood, Osterley, Parsons Green, Preston Road, Ravenscourt Park, Rayners Lane, Redbridge, Rickmansworth, Roding Valley, Ruislip, Ruislip Gardens, Ruislip Manor, Seven Sisters, Snaresbrook, South Ealing, Southfields, Southgate, South Harrow, South Kenton, South Wimbledon, Stamford Brook, Sudbury Hill, Sudbury Town, Totteridge & Whetstone, Turnham Green, Upminster Bridge, Upney, Wanstead, Watford, West Acton, West Harrow, West Ruislip, Wimbledon, Woodford, Woodside Park

8:15am-8:30am: Acton Town, Archway, Arsenal, Blackhorse Road, Boston Manor, Bounds Green, Bow Road, Brent Cross, Brixton, Bromley-by-Bow, Burnt Oak, Canada Water, Canning Town, Dollis Hill, Ealing Broadway, Ealing Common, East Acton, East Finchley, Finchley Road, Finsbury Park, Fulham Broadway, Golders Green, Goldhawk Road, Hammersmith (H&C), Harrow & Wealdstone, Hendon Central, Highgate, Kensal Green, Kilburn, Kilburn Park, Leytonstone, Maida Vale, Manor House, North Acton, North Wembley, Park Royal, Plaistow, Putney Bridge, Queen’s Park, Shepherd’s Bush Market, St. John’s Wood, South Woodford, Swiss Cottage, Tooting Bec, Tooting Broadway, Tottenham Hale, Tufnell Park, Upton Park, Walthamstow Central, Warwick Avenue, Wembley Park, West Brompton, West Finchley, West Hampstead, Willesden Green, Wood Green

8:30am-8:45am: Baker Street, Bank/Monument, Barons Court, Belsize Park, Bermondsey, Caledonian Road, Canary Wharf, Chalk Farm, Earl’s Court, Edgware Road, Elephant & Castle, Euston, Hammersmith, Hampstead, Highbury & Islington, Holloway Road, Kennington, Kentish Town, Ladbroke Grove, Lancaster Gate, London Bridge, Marylebone, Mile End, Moorgate, Notting Hill Gate, Oval, Paddington, Pimlico, Richmond, Royal Oak, Stepney Green, Stockwell, Uxbridge, Vauxhall, Victoria, Westbourne Park, West Kensington, Westminster, Whitechapel

8:45am-9:00am: Barbican, Aldgate East, Blackfriars, Borough, Cannon Street, Chancery Lane, Edgware Road (Bakerloo), Euston Square, Farringdon, Great Portland Street, Latimer Road, Mansion House, Old Street, Regent’s Park, Southwark, St. James’s Park, St. Paul’s, Warren Street

3:30pm-3:45pm: North Ealing

5:00pm-5:15pm: Heathrow Terminal 5

5:15pm-5:30pm: Willesden Junction

5:30pm-5:45pm: Aldgate, Russell Square, South Kensington, West Ham, Heathrow Terminals 1 2 3, Heathrow Terminal 4

5:45pm-6:00pm: Bond Street, Embankment, Goodge Street, Green Park, Gunnersbury, Hanger Lane, Wood Lane, Holborn, King’s Cross St. Pancras, Knightsbridge, Lambeth North, Liverpool Street, Mornington Crescent, North Greenwich, Oxford Circus, Stonebridge Park, Charing Cross, Stratford, Temple, Tower Hill, Turnpike Lane, Upminster, Waterloo, White City

6:00pm-6:15pm: Angel, Camden Town, Covent Garden, East Ham, Gloucester Road, Greenford, High Street Kensington, Hyde Park Corner, Leicester Square, Leyton, Marble Arch, Piccadilly Circus, Queensway, Shepherd’s Bush, Sloane Square, Tottenham Court Road

6:15pm-6:30pm: Bayswater [1], Bethnal Green [2], Clapham Common [2], Clapham North [2], Queensbury [4], Wembley Central [4]

You can explore graphs of the flows, in detail, at Tube Heartbeat – just choose the station of your choice on the drop-down on the top right, or click on it on the map.

Six Rush Hours?

Interestingly, if you look at the flows between stations, you can actually see SIX rush hours each weekday (you can see five of them below by looking across these sample segment graphs):

fiverushhours

These are:

  • A early morning peak, 7-8am. This is distinct from the main morning peak, and can be seen certain segments in east London, particularly on the District line near Plaistow, where the two morning peaks are an hour apart, with a noticeable dip in flow between the two. This may reflect the workforce for some traditional industries with 8am-4pm historical or shift-based working hours.
  • The main morning rush hour that almost all stations and line segments see – 7:30am-9am. Some of the more outlying stations (Zones 5-9) see their peak for this rush hour earlier than 8am, as it takes a while to get into the centre of London. You can see this is not the 7-8am peak above, by “tracing” the ripple through the network towards central London.
  • School home-time at roughly 3-4pm. Mainly affects some smaller, outer London stations, particularly in the north-west, for example Moor Park.
  • A corresponding 4-5pm peak for shift workers who started at 8am. Only a few links show this, such as Wembley Central in north-west London. The evening rush hours are less “compressed” than the morning ones so it is generally harder to distinguish between this one and the next one.
  • The main evening rush hour, 5-7pm.
  • Theatreland end-of-show rush hour, 10-11pm. Noticeable around Leicester Square, Covent Garden and Holborn. Some other areas, with established night-time economies, may also see a slight peak around this time.

You can also see 3+ rush hours in some of the stations, such as Wembley Central, which shows all six:

wembley_max

Tube Heartbeat

tubeheartbeat

Tube Heartbeat is a interactive map that I recently built as part of a commission by HERE, using the HERE JavaScript API. It visualises a fascinating dataset that TfL makes available sporadically – the RODS (Rolling Origin Destination Survey) – which reveals the movements of people on the London Underground network in amazing detail.

The data includes, in fifteen-minute intervals throughout a weekday, the volume of tube passengers moving between every adjacent pair of stations on the entire tube network – 762 links across the 11 lines. It also includes numbers entering, exiting and transferring within each of the 268* tube stations, again at a 15 minute interval from 5am in the morning, right through to 2am. It has an origin/destination matrix too, again at fine-grained time intervals. The data is modelled, based on samples of how and where passengers are travelling, during a specimen week in the autumn – a period not affected either by summer holidays or Christmas shopping. The size of the sample, and the careful processing applied, means that we can be confident that the data is an accurate representation of how the system is used. The data is published every few years – as well as the most recent dataset, I have included an older one from 2012, to allow for an easy comparison.

As well as the animation of the data, showing the heartbeat of London as the the lines pulse with passengers squeezing along them, I’ve including graphs for each station and each link. These show all sorts of interesting stats. For example, Leicester Square has a huge evening peak, when the theatre-goers head for home:

leicestersquare

Or Croxley, in suburban north-west London, with a very curious set of peaks, possibly relating to the condensed school day:

croxley

Walthamstow (along with some other east London stations) has two morning rush-hours with a slight lull between them:

walthamstow

Check the later panels in the Story Map, the intro which appears when first viewing Tube Heartbeat, for more examples of local quirks.

This is my first interactive web map produced using the HERE JavaScript API – in the past, I have extensively used the OpenLayers, as well as, a long while back, Google Maps API. The API was quick to pick up, thanks to good examples and documentation, and while it isn’t quite as full-featured as OpenLayers in terms of the cartography, it does include a number of extra features, such as being quickly able to implement direction arrows along lines, and access to a wide variety of HERE map image tiles. I’m using two of these – a subdued gray/green background map for the daytime, and an equivalent darker one for the evening data. You’ll see the map transition between the two in the early evening, when you “play” the animation or scrub the slider forwards.

Additionally, I’ve overlayed a translucent light grey rectangle across the map, which acts to further diffuse the background map and highlight the tube data on top. The “killer” feature of HERE JavaScript API, for me, is that it’s super fast – much faster than OpenLayers for displaying complex vector-based data on a map, on both computer and smartphone. Being part of the HERE infrastructure makes access to the wide range of HERE map tiles, with their distinctive design, easy, and gives the maps a distinctive look. I have previously used HERE mapping for some cities in the Bike Share Map (& another example), initially where the OpenStreetMap base data was low in detail for certain cities, but now for all new cities I “onboard” to the map. The attractive cartography works well at providing context for the bikeshare station data there, and the tube flow data here.

There is some further information about the project on the HERE 360 blog, and I am looking to publish a more deatiled blogpost soon about some of the technical aspects of putting together Tube Heartbeat.

Stats

Number of stations Number of lines Number of line links between stations
268* 11 762

Highest flows of people in 15 minutes, for the four peaks:

Between stations (all are on Central line)
Morning 8208 0830-0845 Bethnal Green to Liverpool Street
Lunchtime 2570 1230-1245 Chancery Lane to Holborn
Afternoon 7166 1745-1800 Bank/Monument to Liverpool Street
Evening 2365 2230-2245 St Paul’s to Bank/Monument
Station entries
Morning 7715 0830-0845 Waterloo
Lunchtime 1798 1130-1145 Victoria
Afternoon 5825 1730-1745 Bank/Monument
Evening 2095 1015-1030 Leicester Square
Station interchanges
Morning 5881 0830-0845 Oxford Circus
Lunchtime 2060 1330-1345 Oxford Circus
Afternoon 5043 1745-1800 Oxford Circus
Evening 1109** 2215-2230 Green Park
Station exits
Morning 6923 0845-0900 Bank/Monument
Lunchtime 2357 1145-1200 Oxford Circus
Afternoon 7013 1745-1800 Waterloo
Evening 1203 1015-1030 Waterloo

* Bank/Monument treated as one station, as are the two Paddington stations.
** Other stations have higher flows at this time but as a decline from previous peak.

I’m hoping to also, as time permits, extend Tube Heartbeat to other cities which make similar datasets available. At the time of writing, I have found no other city urban transport authority that publishes data quite as detailed as London does, but San Francisco’s BART system is publishes origin/destination data on an hourly basis, there is turnstyle entry/exit data from New York’s MET subway, although only at a four-hour granularity, and Washington DC’s metro also publishes a range of usage data. I’ve not found an equivalent dataset elsewhere in Europe, or in Asia, if you know of one please do let me know below.

tubeheartbeat2

The data represented in Tube Heartbeat is Crown copyright & database right, Transport for London 2016. Background mapping imagery is copyright HERE.

London Panopticon

Panopticon Animation

The London Panopticon utilises the traffic camera feed from the TfL API, which recently (announcement here) added ~6-second-long video clips from the traffic cameras on TfL “red route” main roads, to show the current state of traffic near you. The site loads the latest videos from the nearest camera in each compass direction to you. The images are nearly-live – generally they are up-to-date to within 10-15 minutes. If the camera is “in use” (e.g. being panned/zoomed or otherwise operated by an official to temporarily reprogramme the traffic lights, see an incident etc) then it will blank out. The site is basically just JavaScript, when you view it, your browser is loading the videos directly from TfL’s Amazon cloud-based repository.

The Panopticon continuously loops the video clips, and updates with the latest feed from the cameras every two minutes, the same frequency as the underlying source. If you are not in London or not sharing your location, it will default to Trafalgar Square. I’ve added a special “Blackfriars” one which is where the under-construction Cycle Superhighway North/South and East/West routes converge – during rush hour you can already see bursts of cyclists using the new lanes.

Try it at vis.oobrien.com/panopticon and note that it only works on desktop web browsers (I’ve tested it on Chrome, Firefox and Safari). It didn’t work on Internet Explorer “Edge” when I tested it on a PC. It also does not work on Chrome on Android and by extension probably mobile in general. It possibly uses a lot of bandwidth, so this is perhaps just as well.

I’ve named it after the Panopticon, a concept postulated by Jeremy Bentham, co-founder of University College London, where I work, in the 1800s for easy management of prisons. The Panopticon encourages good behavior, because you can’t see the watcher, so you never know if you are being watched. Kind of like the traffic cameras.

The concept evolved from a special “cameras” version (no longer working) of the London Periodic Table, which was itself a follow-on from CityDashboard, both of which I created at CASA. The source is on GitHub.

londonpanopticon

p.s. If you made it this far, you might be interested in a hidden feature, where you can specify a custom location. Just add ?lat=X&lon=Y to the URL, where the X/Y is your desired latitude/longitude respectively, in decimal coordinates. Example: http://vis.oobrien.com/panopticon/?lat=51.5&lon=0.

London’s Bikeshare Needs A Redistribution of Stations

bikes_journey_day

Here’s an interesting graph, which combines data on total journeys per day on London’s bicycle sharing system (currently called “Santander Cycles”) from the London Data Store, with counts of available bicycles per day to hire, from my own research database. The system launched in summer 2010 and I started tracking the numbers almost from the start.

You can see the two big expansions of the system as jumps in the numbers of available bikes – to all of Tower Hamlets in early 2012, and to Putney and Fulham in late 2013. Since then, the system has somewhat stagnated in terms of its area of availability, although encouragingly at least the numbers of available bikes has remained constant at around 9500, suggesting that at least the operator is on top of being able to maintain and repair the bikes (or regularly source new ones). Some of the individual bikes have had 4000 trips on them. There is a small expansion due in the Olympic Park in spring 2016, but the 8 new docking stations represents only a 1% increase in the number of docking stations across the system, so I doubt it will have a significant impact on the numbers of available bikes for use.

There is a general downward trend in the numbers of uses of each bike per day, since the halycon Olympic days of Summer 2012, over and above the normal seasonal variation, which concerns me. The one-year moving average recently dipped below 3 uses of each bike per day, this summer, and I am not confident it will pick up any time soon. (The occasional spikes in uses/bike, by the way, generally correspond to sunny summer bank holidays, tube strikes and Christmas Day).

To rejuvenate the system and draw in more users, rather than relying on the established commuter and tourist flows which likely dominate the current usage, I am convinced that the system needs to expand – not necessarily in terms of the number of bikes or docking stations, but in its footprint. I think the system would be much improved by dropping the constraining rule on density (which approximates to always having one docking station every 300m) and instead redistributing some of the poorly performing docking stations themselves further out. It’s crazy that, five years on, there are no docking stations in central Hackney, Highbury, or Brixton, three areas with an established cycling culture and easily cycle-able into the centre of London. Conversely, Putney and Tower Hamlets simply don’t need the high density of docking stations that they currently have, except in specific areas (such as around the train/tube stations in Putney, and Canary Wharf).

Ideally we would have a good density of docking stations throughout cycleable London but, as docking stations (and bikes) are very expensive, I would suggest that TfL instead adopts the model used in Bordeaux (below). Here, the city retains a high-dense core serving tourists, commuters and other centrally-based workers, but adopts a much lower density in the suburbs, so that, while tourists can still “run into” docking stations they don’t know about in the centre thanks to the high density, local users can benefit from the facility in their neighbourhood too, even if it requires a little longer walk to get to it.

bikes_bordeaux

Technical note: Before November 2011, the London numbers included bicycles that were in a docking station but not available to hire (i.e. marked as broken). This exaggerates the number of available bikes (and correspondingly reduces the number of hires/bike/day from the true value) in this period by a small amount – typically around 3-5%, an effect I am not considering significant for this analysis.

Living Somewhere Nice, Cheap and Close In – Pick Two!

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Skip straight to the 3D graph!

When people decide to move to London, one very simple model of desired location might be to work out how important staying somewhere nice, cheap, and well located for the centre of the city is – and the relative importance of these three factors. Unfortunately, like most places, you can’t get all three of these in London. Somewhere nice and central will typically cost more, for those reasons; while a cheaper area will either be not so nice, or poorly connected (or, if you are really unlucky, both). Similarly, there’s some nice and cheap, places, but you’ll spend half your life getting to somewhere interesting so might miss out on the London “experience”. Ultimately, you have to pick your favoured two out of the three!

Is it really true that there is no magic place in London where all three factors score well? To see the possible correlations between these three factors, I’ve calculated the ward* averages for these, and have created a 3D plot, using High Charts. Have a look at the plot here. The “sweet” spot is point 0,0,0 (£0/house, 0 score for deprivation, 0 minutes to central) on the graph – this is at the bottom left as you first load it in.

Use your mouse to spin around the graph – this allows you to spot outliers more easily, and also collapse down one of the variables, so that you can compare the other two directly on a 2D graph. Unfortunately, you can’t spin the graph using touch (i.e. on a phone/tablet) however you can still see the tooltip popups when clicking/hovering on a ward. Click/touch on the borough names, to hide/show the boroughs concerned. Details on data sources and method used are on the graph’s page.

The curve away from the sweet spot shows that there is a reasonably good inverse correlation between house prices and deprivation, and house prices and nearness to the city centre. However, it also shows there is no correlation between deprivation and nearness. Newington is cheap and close in, but deprived. Havering Park is cheap and a nice area, but it takes ages to get in from there. The City of London is nice and close by – but very expensive. Other outliers include Merton Village which is very nice – but expensive and a long way out, while Norwood Green (Ealing) is deprived and far out (but cheap). Finally, Bishop’s in Lambeth is expensive and deprived – but at least it’s a short walk into the centre of London.

Try out the interactive graph and find the area you are destined to live in.

kingspark

p.s. If you are not sure where your ward is, try clicking on the blobs within your borough here.

* Wards are a good way to split up London – there are around 600 of them, which is a nice amount of granularity, and importantly they have real-world names, unlike the “purer” equivalent Middle Super Output Areas (MSOAs). Using postcode “outcodes” would be even better, as these are the most familiar “coded” way of distinguishing areas by non-statisticians, but statistical data isn’t often aggregated in this way.

OpenStreetMap: London Building Coverage

osm_londondetail

OpenStreetMap is still surprisingly incomplete when it comes to showing buildings for the London area, this is a real contrast to other places (e.g. Birmingham, New York City, Paris) when it comes to completeness of buildings, this is despite some good datasets (e.g Ordnance Survey OpenMap Local) including building outlines. It’s one reason why I used Ordnance Survey data (the Vector Map District product) rather than OpenStreetMap data for my North/South print.

The map below (click to view a larger version with readable labels and crisper detail, you may need to click it twice if your browser resizes it), and the extract above, show OpenStreetMap buildings in white, overlaid on OS OpenMap Local buildings, from the recent (March 2015) release, in red. The Greater London boundary is in blue. I’ve included the Multipolygon buildings (stored as relations in the OSM database), extracting them direct from OpenStreetMap using Overpass Turbo. The rest of the OSM buildings come via the QGIS OpenStreetMap plugin. The labels also come from OS OpenMap Local, which slightly concerningly for our National Mapping Agency, misspells Hampstead.

The spotty nature of the OSM coverage reveals individual contributions. For example, Swanley in the far south east of the map is comprehensively mapped, thanks presumably due to an enthusiastic local. West Clapham is also well mapped (it looks like a small-area bulk import here from OpenMap) but east Clapham is looking sparse. Sometimes, OpenStreetMap is better – often, the detail of the buildings that are mapped exceeds OpenMap’s. There are also a few cases where OSM correctly doesn’t map buildings which have been recently knocked down but the destruction hasn’t made it through to OpenMap yet, which typically can have a lag of a year. For example, the Heygate Estate in Elephant & Castle is now gone.

The relative lack of completeness of building data in OpenStreetMap, for London, where the project began in 2004, is – in fact – likely due to it being where the project began. London has always an active community, and it drew many of the capital’s roads and quite a few key buildings, long before most other cities were nearly as complete. As a result, when the Bing aerial imagery and official open datasets of building outlines became more recently available, mainly around 2010, there was a reluctance to use these newer tools to go over areas that had already been mapped. Bulk importing such data is a no-no if it means disturbing someone’s prior manual work, and updating and correcting an already mapped area (where the roads, at least, are drawn) is a lot less glamorous than adding in features to a blank canvas. As a result, London is only slowly gaining its buildings on OSM while other cities jumped ahead. Its size doesn’t help either – the city is a low density city and it has huge expanses of low, not particularly glamorous buildings.

An couple of OpenStreetMap indoor tracing parties might be all that’s needed to fix this and get London into shape. Then the OpenStreetMap jigsaw will look even more awesome.

osm_london_2mb

Click for a larger version. Data Copyright OpenStreetMap contributors (ODbL) and Crown Copyright and Database Right Ordnance Survey (OGL).