Skip to content
November 5, 2010 / clayliesstill

Making graphs fit the point

For those who believe that the only solution to cycling in Britain is the construction of ‘Dutch-style’ cycle paths everywhere, there is no room in their narrative that cycling might be increasing in Britain without such facilities.

Therefore these commentators go out of their way to demonstrate that cycling is ‘flatlining’ in Britain. As usual, statistics and graphs are be presented to back up the case.

If I wanted to demonstrate the total failure of British transport policy towards cycling, I couldn’t do any better than display this graph of cycle and private car use from 1949-2009:

Isn’t it terrible?

Yes, from that graph it is clear: cycling in Britain is in terminal decline against the relentless growth in car use.

But wait, what if we compared it to see what has happened in other countries?

Good idea: how about the Netherlands. That’s the place people often refer to as the pinnacle of achievements in cycling, and with good reason – there’s 10 times more cycling per person when compared with the UK.

So, what does the same graph look like with data for the Netherlands?

Wow!

Suddenly the Netherlands doesn’t appear quite as good as we might have thought. Car use appears to have grown at the same rate as in Britain, and cycle use has also gone from a major mode to a tiny one.

But this only happens because of the design of the graph and the choice of units, in this case: billions of kilometres travelled.

Cycling in the Netherlands actually rebounded quite significantly after the nadir in the early 1970s, but that doesn’t appear on a graph when compared with the steady growth in car mileage.

To accurately depict what’s happening, we need to present this data differently. If we want to make a point, then we can leave it as it is.

Advertisements

3 Comments

Leave a Comment
  1. markbikeslondon / Nov 22 2010 11:22 am

    An interesting way of looking at things, and thanks for looking at my page which examines the national modal share of cycling vs other transport methods.

    Sure, car ownership has grown in both the Netherlands and the UK but if you look at the same graph in both countries around the 1950s alone the lines going like this / for car ownership, and in the opposite direction for bike use are clear. In the Netherlands they were able to recover somewhat, in the UK very much less so.

    People use graphs and statistics to prove a point all of the time. For example Transport for London will tell you that the percentage of cyclists riding to work in London has grown by over 100% in the past few years. Sounds great on paper but 100% of not a lot is not a lot more (ie modal share in London is still only about 2%)

    The recent National Travel Survey was clear in showing that bus use, rail use and road use (and indeed private car ownership) have all grown significantly in recent years. On bicycle use they are also clear; “Frequency of bicycle use has remained fairly stable over time since 1998/00. In 2009, 14% of respondents said they ride a bicycle at least once a week and a further 9% said they did so at least once a month. 68% said they use a bicycle less than once a year or never.”

    Regardless of the stats I think it is fair to say that the cycling scene in the UK is in a pretty dire state when compared to the Netherlands and there is much potential for growth here with the right interventions. I happen to think that following the Dutch model is a proven way of growing mass cycling rates and something worth campaigning for here in the UK. Given said poor state of cycling I’d be interested to know what you think could be done better if you don’t want the Dutch model?

    All the best, and thanks for the link / comments,

    Mark

  2. David Arditti / Aug 2 2011 2:03 pm

    The vertical scale of these graphs makes it difficult to see what is going on with cycling. But no, “flatlining” is not the appropriate term in either case. And I think you will find that advocates of segregated cycle infrastructure (like me and Hembrow) tend to use the term “flatlining” when talking about recent trends of cycling in the UK, on a timescale of less than 20 years, to demonstrate the failure of policy during a period when cycling has been officially “promoted”, not the 60 year period presented here.

    Your graphs show that from 1952 to 1970 cycling declined sharply in the UK, and has “flatlined” ever since. Whereas from 1959 to 1977 cycling declined significantly in the NL, and has risen significantly since then, but not back to the mileage it was at in 1959.

    However, I don’t accept that total transport mileages are a good indicator of policy success. Mode share is the important indicator. But another possible indicator is number of trips, which Hembrow uses in the piece to which you link. So I think you are slightly distorting the arguments other people make to make your own point here.

    David

  3. clayliesstill / Aug 2 2011 9:38 pm

    Erm, yes: that’s the point I’m making.

    “the vertical scale of these graphs make it difficult to see what is going on with cycling”. Quite. That’s exactly what Hembrow was doing and what I was criticising!

    Hembrow’s interpretation of statistics is flawed. He is the one distorting the statistics, I am simply pointing out that you can make the point you want by interpreting the statistics the way you choose.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: