Rebasing of growth / decline graphics from 2005 to 2010

[whole diary]

[grahame]

Our website hosts ticketed passenger rail journey data, by station, going back to 2005. Graphics showing growth and decline have been very useful in helping us spot trends, and in helping us see how changes effect the pattern over the years.

The base point of 2005 - the start of my data set - was sensible when I started putting this data together.  But now - as we approach 2016 - graphs based ten years ago give a no-longer-due weight to the changes of ten years ago when we really want to look at the effect of changes in the last five years or so. With this in mind, I have rebased the graphs (and added an extra column to the numbers) with 2010 rather that 2005 being my base point.

Here's an example of the changes to the base, taking all stations in the Bristol postcode area ...





To try thes out ... here's an example URL:
http://www.wellho.net/demo/railuse.php?place=BA^» (British Airways - about)&baseyear=2010
That's Bath (BA postcodes) with a base year "100" of 2010.  Please replace postcode letters and / or year, or complete the form on the bottom of the page at that URL for other areas / base years.

You can also reach these graphs via the "Station Comparator" at the top of each page on the Coffee Shop - select a station, and there's an option in there for the graphic for that postcode region.

[Chris from Nailsea]

Thanks for that fascinating item of graphic work, grahame. 

Purely out of idle curiosity on my part: I wonder what a line on that graph would have looked like for BS20 postcodes - if only the Portishead branch had re-opened in 2005 ... or 2010 ... 

[grahame]

Purely out of idle curiosity on my part: I wonder what a line on that graph would have looked like for BS20 postcodes - if only the Portishead branch had re-opened in 2005 ... or 2010 ... 

Hmm .. the graphic methodology (growth / shrinkage) doesn't really work for a new station as there's nothing to base it on - indeed the graph script intentionally leaves off stations with less than 500 journeys per annum.   A better graphic in those circumstances is based on the number of journeys per head of population in the station catchment (which, however, gives you big arguments about catchments).

[Chris from Nailsea]

Oh, that's all absolutely fine with me, grahame: as I posted, it's merely idle speculation on my part (but probably shared by many Bristol commuters living in Portishead, for example).