How many people live around main railway stations in England and Wales?

A few years ago Alasdair Rae asked in a blog: How many people live in Manchester? It's a simple question, but the answer is far from straightforward. Do you count the population in the district of Manchester, which forms the core of the conurbation? Or is Greater Manchester, now formally a combined authority, the better unit of measurement? And how can you compare this population figure to other core cities? So instead of using administrative boundaries, Alasdair calculated the population figures based on Census 2001 data for those living in a 15 miles radius around the main railway station of Manchester and of the other core cities plus London.

Since this blog from 2008, data from the Census 2011 revealed that many cities gained population since 2001, in particular Manchester with a growth rate of 19%. In many core cities of the main conurbations this growth was driven in particular by large scale residential development in and around city centres realising some of the ideals of the urban renaissance project. So for this blog I updated Alasdair's analysis using 2011 Census data and comparing this to Census 2001 figures, summed up in the following table

I sorted the table by rate of percentage change between 2001 and 2011. It's not surprising to see that London shows the highest growth rate. But it's interesting to note that looking at this spatial scale puts the high growth rate of 19% in the city of Manchester in perspective once the wider city region is included. In comparison Nottingham and Bristol are showing slightly higher growth rates. At the bottom of the table are Newcastle and Liverpool. Despite high growth rates in and around the centres of those cities, developments in the wider city regions were more mixed.
The following map shows the location of the 15 mile buffers in combination with the table. It's worth noting that in some cases the unusual geography of a place makes comparison quite difficult. For example the places near the coast have a much smaller hinterland than the places inland. Furthermore Liverpool also includes parts of Flintshire in North Wales. And particularly the smaller conurbations like Bristol or Nottingham include large areas of rural hinterland in the 15 mile radius.

Some technical notes: I used point data of the location of the main railway stations in the core cities of England plus London and Cardiff, then created 15 mile buffers around these locations. Then I selected all output areas intersected by this buffer and used the figures for usual resident population available as part of the English Output Areas 2011, Clipped and Generalised with Univariate Census 2011 dataset at the UK Data Service. One advantage of using this datasource is that the 2001 population figures are contained in this dataset, recalculated for 2011 OS output area boundaries.