Thursday, 31 January 2013

The colour of London's commute

Today saw the release of detailed Census data on, among other things, the mode of transport those in work use to get to work. One interesting aspect of this is the rising level of cycling in London, as described here by Cyclists in the City. I'll probably be looking at that later in the week, but first here is a map which attempts to summarise the transport mix across all of London in a single image.

(Click to embiggen, and higher-quality PDF here)

What the map shows is the mix of transport to work of residents living in each part of London*, using ONS data at Middle Super Output Area (MSOA) level. Each MSOA is given an RGB colour determined by the modal share, with red colours representing travel by car, taxi or motorbike, blue travel by public transport and green cycling or walking.

The result is a fairly simple pattern, with motor vehicles predominating on London's fringes, public transport in the inner suburbs and cycling and walking in the very centre. Those tendrils of blue reaching out presumably represent major public transport links.

A few details about the mapping technique for anyone who's interested: I was inspired to use the RGB approach by James Cheshire's map of election results and after some trial and error found a fairly simple way to do it in R which I can provide more details of to anyone who asks. The data and boundaries are both from ONS, the former downloaded from Neighbourhood Statistics. The maps exclude those people of working age who are not in work, who work from home or who use some form of transport so strange that ONS only describe it as 'other'.

* Edited this to make it clear that the map is based on place of residence, following @santacreu34's helpful comment.

13 comments:

  1. Thanks for this post. All data is presented by place of residence I suppose. Using the same technique, would it be possible to compare with data by place of work?

    ReplyDelete
    Replies
    1. I would love to see the same. But did the census collect employers's address. I don't think so.

      Delete
    2. I think some previous Censuses did collect the location of the workplace but I'm not sure if this one did or if so how precise it was. In any case, there's no data on it available at the moment that I can see.

      Delete
  2. please tell me, even though the context doesn't support it whatsoever, that you're using "embiggen" in some kind of ironic fashion..?

    ReplyDelete
    Replies
    1. It's a perfectly cromulent word, John.

      Delete
    2. Love it! Kind of Anglo-Saxon

      Delete
    3. oh, ok, you were. i guess that was my preferred answer but somehow i am still disappointed?
      anyway, sorry, i liked the post hence the reason for visiting..

      Delete
  3. Damn, that's much better than my feeble attempts with bar charts :-) Would be keen to have details for use in Brighton!

    Good to see you use much the same exclusions as I do (i.e. those who don't work or work from home). But I do include "other" - it'd be good to find out some definitions from ONS!

    By the way, for john, the census doesn't collect details on place of work.

    ReplyDelete
  4. Hi - great piece and graphic. I'd love to use the map on CPRE London's Transport page - crediting you. Could you poss send me a higher res picture though?

    Thanks!

    Rosalie@cprelond.org.uk

    ReplyDelete
  5. Nice post! Can we see the R code, please?! Thanks!

    ReplyDelete
  6. Sure, here it is https://www.dropbox.com/s/6s7dv8662cch7f8/Maps%20-%20Commute%20RGB%20map.R

    ReplyDelete
  7. Nice Map Jim! It reminds a bit the The Racial Dot Map but using a different approach to the dataviz http://demographics.coopercenter.org/DotMap/

    anyway, James is really a great expert on visualizing spatial data in R. He was also my inspiration to make this map here:

    http://urbandemographics.blogspot.co.uk/2015/03/mapping-transit-system-of-rio-with-gtfs.html

    ReplyDelete
    Replies
    1. Thanks Rafael! I love your Rio map - it's a shame Transport for London don't (as far as I know) publish GTFS data or someone could do something similar for London.

      Delete

Note: only a member of this blog may post a comment.