Category: London

Categories
London

Taking the Scenic Route – Quantitatively?

A friend forwarded me this article which discusses this paper by researchers at the Yahoo Labs offices in Barcelona and the University of Turin. The basic idea is that they crowdsourced prettiness of places in central London, via either/or pairs photographs, to build up a field of attractiveness, then adjusted a router based on this map, to divert people along prettier, happier or quieter routes from A to B, comparing them with the shortest pedestrian routes. The data was augmented with Flickr photographs with associated locations and appropriate locations. and The article that featured this paper walked the routes and gives some commentary on the success.

Quantitatively building attractive routes is a great idea and one which is only possible with large amounts of user-submitted data – hence the photos. It reminds me of CycleStreets, whose journey planner, for cyclists, not only picks the quickest route, but adds in a quieter (and “best of both worlds”) alternative. Judging locations by their attractiveness also made me think of the (soon to be retired) ScenicOrNot project from MySociety which covered the whole of the UK, but at a much less fine-grained scale – and without the either/or normalisation.

In the particular example that the paper uses, the routes are calculated from Euston Square Station, which happens to be just around the corner from work here, to the Tate Modern gallery. It’s a little over 2 miles by the fastest route, and the alternatives calculated are only a little longer:
quercia_beauty
Above: Figure from http://dx.doi.org/10.1145/2631775.2631799

I really like the concept and hope it gets taken further – for more places and more cities. However, I would contend that local knowledge, for now, still wins the day. The scenic route misses out the Millennium Bridge which is surely one of the most scenic spots in all of London with its framed views to St Paul’s Cathedral and the Tate Modern itself. The quiet route does go this way, but the route is far from quiet when you consider the hordes of tourists normally near the cathedral and on the bridge. The pretty route goes down Kingsway which is a pretty ugly, heavily trafficked route, ignoring the nearby Lincoln Inns Fields, which is lovely. I think that the following, manually curated 3.0 mile route wins out as a much more beautiful route than the algorithmically calculated one:

beauty

Highlights include:

  • Walking through UCL’s Front Quad, through the university campus
  • Down Malet Street, past the imposing Senate House
  • Walking through the Great Hall of the British Museum
  • Bloomsbury Square garden and Lincoln’s Inn Fields
  • Chancery Lane
  • New Street Square (modern but attractive)
  • The statue of Hodge, Dr Johnson’s Cat
  • Wine Office Court, with the Ye Olde Cheshire Cheese Pub
  • Fleet Street and Ludgate Hill, with the famous view to St Pauls
  • The vista from St Paul’s Cathedral, across the Millennium Bridge to the Tate Modern.

Maps in this article are © Google Maps.

Categories
London

Crossrail Site Tour: Tottenham Court Road

Crossrail organised a number of tours of their major worksites, as apart of Open Doors, this weekend, for civil engineering students and other interested parties. One of the sites was the Dean Street box, which will form the western ticket hall at the Tottenham Court Road Crossrail station. While the eastern ticket hall will connect directly with the existing Underground station (for the Central and Northern lines), the western ticket hall is quite some distance away, and in fact is nearly half way towards Oxford Circus – it will also connect to the other lines, via new pedestrian tunnels, but it will be a long walk! The Dean Street box is a huge site itself, with six distinct levels, and yet only a small part of what Tottenham Court Road station will become in 2018:
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The challenges of the site itself are illustrated just by getting to it – access is via the pavement on Oxford Street. As soon as the pavement barrier is drawn across and the doors open, the narrow pavement quickly crowds up with pedestrians, while numerous buses and angry, revving taxis, continue to squeeze along the street.

The Crossrail platforms will stretch between the two ticket halls, and space has been made for a future extension. Crossrail 2, should it be built, will have platforms here, in further tunnels crossing below these new platform tunnels, perpendicularly and approximately half-way between the ticket halls. Some of the pedestrian passageway tunnels, which also run between the two ticket halls, have sections which will connect with the equivalent for Crossrail 2, the extent of which appears in outline on the main site diagram. Planning ahead.

The first thing that strikes you when in the “box” is the huge number of old boiler pipes that are being used to brace the outer wall and stop the pressure of the London clay behind (which has been compressed from buildings over hundreds of years) from collapsing it. The boiler pipes near the top are smaller as they have less pressure to withstand. Some of the larger ones are starting to be removed now as the lower levels of the station ticket hall start to be structurally complete. The pressures are so huge that the engineering team is wary of suddenly removing one and causing any unwanted movement – so they are cutting notches in them to allow the pipes to continue to hold a weaker load, before removing them once the force has been almost entirely redistributed elsewhere.

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Here, reached by a very large number of steps down a couple of gantries, you can see the western end of the eastbound Crossrail platform tunnel. I initially thought that the line of yellow struts was showing the platform itself starting to be built, but actually I think it is marking the “floor” upon which the rails will be laid, as it lies right in the middle of the tunnel, and so the platform level would be marked approximately by the line of lights to the right:
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I was surprised to see the quite noticeable curve of the platform tunnel, to the right – I assumed they’d all be straight, which would enable easy boarding for those on wheelchairs and future platform-edge doors. Perhaps, should the latter happen, there will be some kind of mechanical gap infilling?

Looking in the other direction is the running tunnel, large by tube standards but much smaller than the platform tunnel, where trains will pass along from Bond Street station to here. Because the Dean Street box was excavated before the tunnel boring machine passed through, a tube of foam concrete was added back in, to give the tunnel boring machine something to push against as it passed through. The machine continued to line its tunnel in the box and the platform area, with concrete slabs like you can see below here, but with lower quality, weaker “sacrificial” slabs as they were then bulldozed shortly again after the machine had passed through:
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It was somewhat eerie peering into the silent tunnel, with not a workman in sight, deep below the bustling streets of central London. Largely empty at the moment, with a couple of grooves in the base slab showing where the construction mini-railway had its tracks. Come December 2018, there will be up to one train every two minutes passing along here, so it will not be nearly as silent. Looking into this tunnel there is a noticeable gradient downwards. As trains travel upwards towards here, into the station, the slope will help slow them down, saving energy on braking.

Various parts of the worksite are being built to different specifications – much of the concrete structure will be clad and so not visible to the public, but there are some parts where concrete pillars will be visible features. So, some experimentation is currently taking place to test the quality of finish they can produce with the processes on site. Here is a test pillar that they are quite happy with already, but they think they can do an even better job when they put them in the appropriate place:
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The edge of the western ticket hall box is immediately behind the pillar – notice the much coarser surface, as this will be covered with additional walls and claddings, so it will never be seen by the public. There is also quite a distinct colour/texture change line, running horiztonally along and reflecting different soil/clay conditions behind it.

Thanks to Crossrail and the contractors (Laing O’Rourke) for organising the tours and to the staff on site for showing us their site and enthusing on their work. At TCR, they assembled a PPE-free route through the site, allowing us (mainly civil engineerings students, only a few of the “general public”) to get right into the construction area and get an excellent feel of what is going on and the challenges of such a place. It is extremely tidy for such a complex construction site – with multiple levels having simultaneous construction, they have no choice but to keep everything super-organised. Various walkways have yellow lines and blue “walkway” silhouettes on the ground – somewhat reminiscent of the lines you have to walk along between the bottom of steps from an aircraft and the terminal building. Everything about Crossrail is on a grander scale than London’s existing transport infrastructure, and it will be most impressive seeing the completed stations, which are set to become major London destinations.

The old and the new:
IMG_3013

Categories
Bike Share London

Seeing Red: 15 Ways the Boris Bikes of London Could be Better

santabikes

A big announcement for the “Boris Bikes” today, aka Barclays Cycle Hire. London’s bikeshare system, the second largest in the western world after Paris’s Velib and nearly five years old, will be rebranded as Santander Cycles, and the bikes with have a new, bright red branding – Santander’s corporate colour, and conveniently also London’s most famous colour. As well as the Santander logo, it looks like the “Santa Bikes” will have outlines of London’s icons – the above publicity photo showing the Tower of London and the Orbit, while another includes the Shard and Tower Bridge. A nice touch to remind people these are London’s bikes.

velibIt’s great that London’s system can attract “big” sponsors – £7m a year with the new deal – but another document that I spotted today reveals (on the last page) that, despite the sponsorship, London’s system runs at a large operating loss – this is all the more puzzling because other big bikeshare systems can (almost) cover their operating costs – including Washington DC’s which is both similar to London’s in some ways (a good core density, same bike/dock equipment) and different (coverage into the suburbs, rider incentives); and Paris’s (right), which has a very different funding model, and its own set of advantages (coverage throughout the city) and disadvantages (little incentive to expand/intensify). What are they doing right that London is not?

In financial year 2013/4, London’s bikeshare had operating costs of £24.3m. Over this time period, the maximum number of bikes that were available to hire, according to TfL’s Open Data Portal was 9471, on 26 March 2014. This represents a cost of just over £2500 per bike, for that year alone. If you look at it another way, each bike is typically used three times a day or ~1000 times a year, so that’s about £2.50 a journey, of which, very roughly, the sponsor pays about £0.50, the taxpayer £1 and the user about £1. In those terms it does sound better value but it’s still a surprisingly expensive system.

As operating costs, these don’t include the costs of buying the bikes or building the docking stations. Much of the cost therefore is likely ocurring in two places:

  1. Repairing the bikes – London’s system is wildly* successful, so each bike sees a lot of use every day, and the wear and tear is likely to be considerable. This is not helped by the manufacturers of the bikes going bust a couple of years ago – so there are no “new” ones out there to replace the older ones – New York City, which uses the same bikes, is suffering similar problems. (* Update: To clarify, based on a comment from BorisWatch, this assertion is a qualitative one, based on seeing huge numbers of the bikes in use, in certain places at certain times of the day. Doubtless, some do remain dormant for days.)
  2. Rebalancing/redistribution activity, operating a fleet of vehicles that move bikes around.

I have no great issues with the costs of the bikes – they are a public service and the costs are likely a fraction of the costs of maintaining the other public assets of roads, buses, railway lines – but it is frustrating to see, in the document I referred to earlier, that the main beneficiaries are in fact tourists (the Hyde Park docking stations consistently being the most popular), commuters (the docking stations around Waterloo are always popular on weekdays), and those Londoners lucky enough to live in Zone 1 and certain targeted parts of Zone 2 (south-west and east). Wouldn’t be great if all Londoners benefited from the system?

Here’s 15 ways that London’s bikeshare could be made better for Londoners (and indeed for all) – and maybe cheaper to operate too:

  1. Scrap almost all rebalancing activity. It’s very expensive (trucks, drivers, petrol), and I’m not convinced it is actually helping the system – in fact it might be making it worse. Most cycling flows in London are uni-directional – in to the centre in the morning, back out in the evening – or random (tourist activity). Both of these kinds of flows will, across a day, balance out on their own. Rebalancing disrupts these flows, removing the bikes from where they are needed later in the day (or the following morning) to address a short-term perceived imbalance that might not be real on-the-ground. An empty docking station is not a problem if no one wants to start a journey there. Plus, when the bikes are in sitting in vans, inevitably clogged in traffic, they are of no use to anyone. Revealingly, the distribution drivers went on strike in London a few months ago and basically everything carried on as normal. Some “lightweight” rebalancing, using cycle couriers and trailer, could help with some specific small-scale “pinch points”, or responding to special events such as heavy rainfall or a sporting/music event. New York uses cyclists/trailers to help with the rebalancing.
  2. Have a “guaranteed valet” service instead, like in New York. This operates for a certain number of key docking stations at certain times of the day, and guarantees that someone can start or finish their journey there. London already has this, to a certain extent, at some stations near Waterloo, but it would be good to highlight this more and have it at other key destinations. This “static” supply/demand management would be a much better use of the time of redistribution drivers.
  3. rrrHave “rider rewards“, like in Washington DC. Incentivise users to redistribute the bikes themselves, by allowing a free subsequent day’s credit (or free 60-minute journey extension) for journeys that start at a full docking station and end at an empty one. This would need to be designed with care to ensure “over-rebalancing”, or malicious marking of bikes as broken, was minimised. Everyone values the system in different ways, so some people benefit from a more naturally balanced system and others benefit from lower costs using it.
  4. Have more flexible user rules. Paris’s Velib has an enhanced membership “Passion” that allows free single journeys of up to 45 minutes rather than every 30 minutes. London, like Paris, is a large city, and the current 30 minute cutoff seems short and arbitrary, when considering most bikes are used around three times a day. Increasing the window would therefore have little impact on the overall distribution of the system and might in fact benefit it – because the journeys from the terminal stations to the City or the West End, which are the most distinctive flows seen, are acheived comfortably in under half an hour. In London, you have to wait 5 minutes between hires, but most systems (Paris, Boston, New York) don’t have this “timeout” period. To stop people “guarding” recently returned bikes for additional use, an alternative could be make it a 10 minute timeout but tie it to the specific docking station (or indeed a specific bike) rather than system-wide. Then, if people are prepared to switch bikes or docking stations, they can continue on longer journeys for free.
  5. Adjust performance metrics. TfL (and the sponsors) measure performance of the system in certain ways, such as the time a docking station remains empty at certain times of the day. I’m not sure that these are helpful – surely the principle metric of value (along with customer service resolution) is the number of journeys per time period and/or number of distinct users per time period. If these numbers go down, over a long period, something’s wrong. The performance metrics, as they stand, are perhaps encouraging the unnecessary and possibly harmful rebalancing activity, increasing costs with no actual benefit to the system.
  6. lyonRemove the density rule (one docking station every ~300 metres) except in Zone 1. Having high density in the centre and low density in the suburbs works well for many systems – e.g. Bordeaux, Lyon (above) and Washington DC, because it allows the system to be accessible to a much larger population, without flooding huge areas with expensive stations/bikes. An extreme example, this docking station is several miles from its nearest neighbour, in a US city.
  7. Build a docking station outside EVERY tube station, train station and bus station inside the North/South Circular (roughly, Zones 1-3). Yes, no matter how hilly* the area is, or how little existing cycling culture it has – stop assuming how people use bikes or who uses them! Bikeshare is a “last mile” transport option and it should be thought of as part of someone’s journey across London, and as a life benefit, not as a tourist attraction. The system should also look expand into these areas iteratively rather than having a “big bang” expansion by phases. It’s crazy that most of Hackney and Islington doesn’t have the bikeshare, despite having a very high cycling population. Wouldn’t be great if people without their own bikes could be part of the “cycling cafe culture” strong in these places? For other places that have never had a cycling culture, the addition of a docking station in a prominent space might encourage some there to try cycling for the first time. (*This version of the bikes could be useful.)
  8. Annual membership (currently £90) should be split into peak and off-peak (no journey starts from 6am-10am) memberships, the former increased to £120 and the latter decreased back to £45. Unlike the buses and trains, which are always full peak and pretty busy off-peak too, there is a big peak/offpeak split in demand for the bikes. Commuters get a really good deal, as it stands. Sure, it costs more than buying a very cheap bike, but actually you aren’t buying the use of a bike – you are buying the free servicing of the bike for a year, and free distribution of “your” bike to another part of central London, if you are going out in the evening. Commuters that use the bikes day-in-day-out should pay more. Utility users who use the bike to get to the shops, are the sorts that should be targetted more, with off-peak membership.
  9. officialmapA better online map *cough* of availability. The official map still doesn’t have at-a-glance availability. “Rainbow-board” type indications of availability in certain key areas of London would also be very useful. Weekday use, in particular, follows distinct and regular patterns in places.
  10. Better indication of where the nearest bikes/docks are, if you are at a full/empty docking station, i.e. a map with route indication to several docking stations nearby with availability.
  11. Better static signage of your nearest docking station. I see very few street signs pointing to the local docking station, even though they are hard-built into the ground and so generally are pretty permanent features.
  12. Move more services online, have a smaller help centre. A better view of journeys done (a personal map of journeys would be nice) and the ability to question overpayments/charges online.
  13. hubwayEncourage innovative use of the bikeshare data, via online competitions – e.g. Boston’s Hubway data visualisation competitions have had lots of great entries. These get further groups interested in the system and ways to improve it, and can produce great visuals to allow the operator/owner to demonstrate the reach and power of the system.
  14. Allow use of the system with contactless payment cards, and so integration with travelcards, daily TfL transport price caps etc. The system can’t use Oyster cards because of the need to have an ability to take a “block payment” charge for non-return of the bikes. But with contactless payment, this could be achieved. The cost of upgrading the docking points to take cards would be high, but such docking points are available and in use in many of the newer US systems that use the same technology.
  15. Requirement that all new housing developments above a certain size, in say Zone 1-3 London, including a docking station with at least one docking point per 20 residents and one new bike per 40 residents, either on their site or within 300m of their development boundary. (Update: Euan Mills mentions this is already is the case, within the current area. To clarify, I would like to see this beyond the current area, allowing an organic growth outwards and linking with the sparser tube station sites of point 7.)

London has got much right – it “went big” which is expensive but the only way to have a genuinely successful system that sees tens of thousands of journeys on most days. It also used a high-quality, rugged system that can (now) cope with the usage – again, an expensive option but absolutely necessary for it to work in the long term. It has also made much data available on the system, allowing for interesting research and increasing transparency. But it could be so much better still.

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Washington DC’s systems – same technology as London’s, not that much smaller, but profitable.

Categories
Leisure London

Book Review: The Capital Ring

capitalringThe Capital Ring, by Colin Saunders, is an guide to walking the eponymous route, a 78 mile circular walk around inner London (generally Zones 3-4), one of London’s official long-distance walking trails.

The book, a new (2014) edition, is presented in an attractive, compact format with rounded corners, so ideal for chucking in a bag when walking the trail. The new edition means that the book will have taken into account minor changes to the route that happen from time to time due to housing developments and other aspects of London’s continuing evolution. The route is split up into 15 sections, all between 3 and 8 miles long and generally starting/finishing at or near stations (with short link sections where necessary).

The book makes excellent use of Ordnance Survey Explorer (1:25000) mapping, with different map excerpts for each mile or so of the trail, appearing inline with the route description. The route itself is overlaid in yellow on these maps. Generally, this makes the map useful for navigating, except in some small sections where the route is complicated and the yellow line is a little broad and the scale a bit small (the Ordnance Survey’s own “official” green diamond marks for the route also appear on the maps, which can further confuse). There, you’ll need to follow the route description carefully. The route itself is waymarked on the ground with posts and signs but sometimes these are missing, which is where the book comes in particularly useful.

The clear and concise route descriptions, and annotated mapping, are augmented by short descriptions of features and trivia of local interest. The walk generally passes through interesting parts of London all the way long, so the book has many such pieces. Some of these are illustrated by photographs:

capitalring_page

Your reviewer test-walked a section near Stoke Newington and found the guide’s navigation effective, and learnt some new things about an area he thought he knew well! If you are looking for a good walk and a great guide to it, that illuminates just how green and varied London’s “inner city” is, you could do a lot worse than with this book.

Get it here on Amazon: Capital Ring. (Make sure you get the newest edition, reviewed here, which has an orange cover.)

Thanks to publisher Aurum Press for sending me a review copy. ISBN 9781781313374. List price is £12.99.

Categories
London

London Boroughs and Tube Lines

piccadilly

How many of London’s 32 boroughs (& the City of London) would you pass through on a single end-to-end journey on the tube?

It turns out that if you travel the length of the Piccadilly Line (Uxbridge branch), then, in a single journey, you’ll pass through 14 boroughs (and stop at least once in all of them but Barnet). That’s more of London than if you travel on any single Crossrail journey, once it opens in 2018.

Line Branch # Boroughs
with Stops		 # Boroughs
(Total)
Piccadilly to Uxbridge 13 14
Crossrail to Shenfield 10 13
Central to West Ruislip 11 12
Piccadilly to Heathrow 11 12
Central to Ealing Broadway 10 11
Northern High Barnet to Morden 10 10
District Upminster to Richmond/Ealing Broadway 10 10
Overground Richmond to Stratford 8 10
District Wimbledon to Barking 9 9
Hammersmith & City 9 9
Jubilee 9 9
Northern Edgware to Morden via Bank 9 9
Overground Clapham Junction to Stratford 8 9
Northern Edgware to Morden via Charing Cross 8 8
Bakerloo 5 8
Overground West Croydon to Highbury & Islington 7 7
Metropolitan 7 7
Circle 7 7
Victoria 6 7
Overground Clapham Junction to Highbury & Islington 6 7
Overground Gospel Oak to Barking 6 6
Overground Watford Junction to Euston 3 6
District Wimbledon to Edgware Road 5 5
DLR Bank to Lewisham/Woolwich Arsenal 4 4
Tramlink Wimbledon to New Addington 3 3
Waterloo & City 2 3
Cable Car 2 2

See for yourself at http://vis.oobrien.com/tube/#map.

Of course, if you are aiming to see a cross-section of London’s boroughs, in a rush, then the tube probably isn’t the best way, as you’ll be underground for quite a lot of the journey…

Categories
London Olympic Park

Queen Elizabeth Olympic Park – New Bridge

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There’s a new bridge into the Queen Elizabeth Olympic Park – the Monier Bridge. It connects Monier Road in Fish Island, part of Hackney Wick, with the Loop Road in the Olympic Park. At the latter connection point there is a new ramp down to the canal towpath and also a path through the Sweetwater development site, to Carpenters Lock which is the focal point of the whole park, as it connects the main north and south parts. The new bridge was actually installed a couple of years ago, but it has taken a long time to open up the area of the park north-west of the Olympic Stadium and so provide the link through to the centre.

The bridge’s design mirrors that of the Wallis Bridge which connects the northern half of Hackney Wick to the park. A map, that I found on hoardings beside another bridge in the park which is being narrowed, shows both new bridges (on the extract of the map below, they are both on the left-hand side) and also reveals new names for several other bridges in the park. The bridge to the Waterpolo arena, aka the Stratford Waterfront development site, is now called Tallow Bridge. Further downstream, the Aquatic Bridge and Purple Bridge become the Thornton Bridge and Iron Bridge respectively.

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Elsewhere, I noticed that the hoardings around the Sweetwater development site have a new mural on them. There is also a new ramp down to the canal from the White Post Lane entrance, alongside the existing steep and cobbly one. There are also five new level paths connecting the canal with the old Main Press Centre building. The larger building alongside, Here East, which has previously always been a drab white and grey, has a huge “H” painted in black and green on its southern face, along with a huge “HereEast.com” graphic.

With the new bridge having opened above, and Carpenters’ Road finally reopened under the mainline railway, the Queen Elizabeth Olympic Park finally has all almost all of its entrances open – it’s somewhat challenging to count them all, but there’s at least 30 now, depending on how the boundaries are defined. Certainly, this is a big piece of London which is now a lot more connected – and a lot less secluded – than it was back in 2007.

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Categories
Data Graphics London

North/South – The Interactive Version.

northsouth_large

As a weekend project, I’ve made an interactive version of my London North/South artwork.

As well as the blue and red house silhouettes, assembled in QGIS, I’ve added in GeoJSON files of the River Thames (from Ordnance Survey Vector Map District, like the buildings) and of tube/DLR/Overground stations – the location/name/network data is from this GitHub file and I’ve applied a custom styling in OpenLayers 2, with station name styling inspired by the NYC Subway signs. The positional information comes from an OpenLayers control – I’m using a utility function to modify the output to use degrees, minutes and seconds. Finally, the naming popup is a set of UTFGrid JSON files (with 2-pixel resolution) based on OpenStreetMap data for polygons. Where the polygon has a building, leisure or waterway tag, I’m extracting a name, if available, and showing it. The coverage here is therefore only as good as building naming is in OpenStreetMap. I could potentially add in street names in the future.

Try it out here.

Categories
Data Graphics London

All the Tweets

Cross-posted from Mapping London, edited slightly.

This is a map of geolocated Tweets for the whole world – I’ve zoomed into London here. The map was created by Eric Fischer of Mapbox, who collected the tweets over several years. The place where each tweet is posted from is shown by a green dot. There are millions and millions of tweets on the global map – in fact, over 6.3 billion. The map is zoomable and the volume of tweets means that popular locations stand out even at a high zoom level. The dots are in fact vectors, so retain their clarity when you zoom right in. The map is interactive – pan around to explore it.

If you think this looks familiar, you’d be right. Mapping London has featured this kind of social media ‘dot-density mapping’ a few times before, including with Foursquare and Flickr (also Eric’s work), as well as colouring by language. The key difference with this latest map is the sheer volume of data. By collecting data on geolocated tweets over the course of several years, globally, Eric has assembled the most comprehensive map yet. He has also taken time to ensure the map looks good at multiple zoom levels, by varying the dot size and dot density. He’s also eliminated multiple tweets that happen at the exact same location, and reduced some of the artefacts and data quality issues (e.g. straight lines of constant latitude or longitude) to produce perhaps the cleanest Twitter dot-density map yet. Zooming out makes the map appear somewhat similar to the classic night-time satellite photos of the world, with the cities glowing brightly – here, London, Paris and Madrid are prominent:

activity_westeurope

However it should still be borne in mind that while maps of tweets bear some relationship to a regular population density map at small scales, at large scales they will show a bias towards places where Twitter users (who may be more likely to be affluent and younger than the general population) live, work and socialise. The popularity of the social network also varies considerably on a country-by-country basis. Some countries will block Twitter usage altogether. And in other countries, the use of geolocated tweets is much less popular, either due to popularity of applications that do not record location by default or a greater cultural awareness of privacy issues relating to revealing your location when you tweet.

activity_edinburgh

Above: Twitter activity in central Edinburgh, proving once and for all that the East End is a cooler place than the West End.

From the Mapbox blog. Found via Twitter, appropriately. Some of the background data is © OpenStreetMap contributors, and the map design and technology is © Mapbox.

Categories
London

Book Review: London Buildings – An Architectural Tour

londonbuildings

This book, which features great examples of London building architecture, is itself distinctively designed and immaculately presented. It’s been out for a couple of years now, however I was recommended it when purchasing another book recently on Amazon, as an impulse purchase, it’s an excellent find.

The book was authored by Hannah Dipper and Robin Farquhar of People will always need plates and is based on their heavily stylised interpretation of the buildings featured.

Each building featured in the book – there are around 45 – gets a two page spread, always in the same format – the building shown in white with clean strokes of detail in black, and a distinctive, single tone of colour for the sky. A small inset box includes the buliding name, architects, age and 100 words. That’s it.

The book doesn’t just feature the modern Brutalist London landscape (e.g. Trellick Tower), and the latest modern skyscrapers (e.g. the Gherkin) it also includes such older gems as Butler’s Wharf and the Dulwich Picture Gallery. These two are treated to the wonderful, minimalistic sketch style, with just the two colours allowing the design detail of the building itself to take centre stage.

On Amazon: London Buildings: An Architectural Tour, currently for £9.99. Published by Batsford, an imprint of Anova Books.

Image from the London Design Guide website.

Categories
London OpenStreetMap

OpenStreetMappers of London

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I contributed a number of graphics to LONDON: The Information Capital, a book co-written by Dr James Cheshire, also of UCL Geography. Two of my graphics that made it into the book were based on data from OpenStreetMap, a huge dataset of spatial data throughout the world. One of the graphics, featured in this post, forms one of the chapter intro pages, and colours all the roads, streets and paths in the Greater London Authority area (around 160,000 “ways” which are discrete sections of road/path) according to the person who most recently updated them. Over 1500 indivdual users helped create and refine the map, and all are featured here. I was pleased to discover I was the 21st most prolific, with 1695 ways most recently modified by myself at the time that the graphic was produced.

The more active users will typically have areas around home and work which they intensively map, plus other, smaller areas such as contributions made during a mapping party or other social event organised by/for the London OSM community. Here’s an example filtering for just one user:

osm_dan

Putting the users together reveals a patchwork of key authors and more minor contributors, together forming a comprehensive map of the city. Detail levels vary, partly as the fabric of the city varies from area to area, but also as some contributors will be careful to map every path and alleyway, while others will concentrate on the driveable road network.

osm_detail

The data was obtained from a local copy of the OpenStreetMap database, for Great Britain, that I maintain for various pieces of work including OpenOrienteeringMap. You can obtain the data files from GeoFabrik (this link is to their new London-only version). The data was captured in early February 2014. Newham borough in east London (light blue) shows up particularly prominently because it looks like it had had a bulk update of all roads there by a single user, just before the capture, to indicate which were lit by streetlights (lit=yes).

I used QGIS to assemble the data and applied the temp-c colour ramp, classifying across all the contributors – I then changed the ones which were assigned a white colour, to green. The colours used in the book are slightly different as some additional editing took place after I handed the graphic over. The colour ramp is relatively coarse, so multiple users will have the same colour assigned to them. The very long tail of OSM contributions (where only a small number of people make the great majority of edits) mean that this still means that most major contributors have a unique colour assigned to them.

osm_book


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Note that these files actually are for an area that is slightly larger than the Greater London Authority extent – a buffer from Ordnance Survey Open Data Boundary-Line is used to mask out the non-GLA areas.

If you like this thing, it’s worth noting that Eric Fischer independently produced a similar graphic last year, for the whole world. (Interactive version).