Dispensing with the doughnut?

Focusing on centres contained within the ‘doughnut’, defined by the area between the north-south circular and M25, has worked well so far in getting us thinking about the right kind of areas and looking at relevant town centres. It would be preferable though if we could define our catchment area some other way, not least because upholding a more or less aspatial zoning approach to urban planning is something we wish to avoid. Could we compile a dataset that would let us capture (approximately) all the town centres within a given journey time from central London boroughs using different forms of transport? This would make more sensitive to a multi-scaled approach by identifying cooridorrs and barriers to access at the regional scale. It wold also give a better impression of polycentric structures if eqivalent data for travel between different centres could be added. By treating this as a background layer for analytical purposes we can still concentrate our research ‘bottom-up’ from the town-centres themselves but within a regional context that is not artificially restricted to the doughnut.