3. Methodology

Data Sources

The Scottish Government Urban Rural Classification 2022 was created by combining population and accessibility information to distinguish between urban and rural areas across Scotland.  Population information is sourced from the Census 2022 Settlements dataset provided by National Records of Scotland (NRS), and accessibility information is obtained by calculating drive times from the centres of Settlements with a population of 10,000 or more (i.e. Large and Other Urban Areas).  Table 3.1 summarises the datasets used to create the 2022 version of the classification.

Settlements define contiguous built-up areas in Scotland and, along with Localities, are generally more identifiable as the traditional towns and cities than administrative boundaries such as Local Authorities, much of which consist of land that is not developed and unpopulated.  The Settlements dataset is produced by NRS, with the Census 2022 version having been released in May 2024.  Census 2022 population and households data, together with information on non-residential addresses from the Royal Mail Postal Address File, were used to classify 2022 postcodes as high or low density.  A Settlement is defined to be a group of high-density postcodes whose combined population rounds to 500 people or more.  They are separated by low density postcodes.  Further information on how Settlements are created can be found on the NRS website.

Settlement centroids for Carlisle and Berwick-upon-Tweed in Northern England were also included in the analysis as they have populations of over 10,000 and are within a 30-minute drive of the Scottish border, and thus will influence accessibility results.  For consistency, the same centroids which were used in 2013-14, 2016, and 2020 Classifications were used in the 2022 analyses.  These were based on the OS 50k Gazetteer product.

Transport Network Creation

For the calculation of drive times, a network dataset including road and ferry routes was required.  Roadways were obtained from Ordnance Survey (OS) National Geographic Database (NGD) Transport Network for Scotland with an extension beyond the border to include routes for Northern England. OS NGD Transport Network gives a current, comprehensive network view of Great Britain's roads.  In the previous 2020 Classification, another OS product – OS Highways - was used.  Further information on the new road speeds included in OS NGD Transport and their impact on the Urban Rural Classification can be found in the Changes with this Release section. 

The Scottish Government maintain a dataset of Scotland’s ferry routes which have been digitised against OS background mapping. Both vehicle and passenger only services are included in the SG Ferry Routes, though only the vehicular routes are used within the Urban Rural analysis. The journey duration can be calculated from online timetables, and the outputs account for a 30-minute boarding time being added for the drive times.

Analysis and Classification

The first stage in creating the classification is to categorise the Settlements dataset using the population thresholds of 125,000, 10,000 and 3,000 to identify the Settlements from which drive times will be calculated.  Settlements were grouped into the following categories:

(1) Large Urban Areas - populations of 125,000 or more

(2) Other Urban Areas - populations of 10,000 to 124,999

(3) Small Towns - populations of 3,000 to 9,999

(4) Rural Areas - populations less than 3,000

The next step was to distinguish between accessible and remote areas.  The drive times were calculated from the centroids of the Settlements with a population of 10,000 or more (i.e. Large and Other Urban Areas).  The drive time analysis was performed using GIS software (ESRI ArcGIS Pro Network Analyst extension).  The following definitions of remoteness were defined:

(1) Accessible – areas within a 30 minute drive time of a Settlement with a population of 10,000 or more.

(2) Remote – areas that are more than a 30 minute drive time (6-fold classification), or areas that have a drive time more than 30 minutes but less than or equal to 60 minutes (8-fold classification) from a Settlement with a population of 10,000 or more.

(3) Very Remote – areas that are more than a 60 minute drive time from a Settlement with a population of 10,000 or more (8-fold classification only).

Accessibility categories were assigned to the Settlement boundary layer based upon the location of the Settlement population weighted centroids.  Classifying the settlements by their centroids means that the entire settlement will be assigned to a single class, regardless of whether the area is split by the drive time extent boundary.

The re-classified settlement boundaries and drive time datasets were combined to form one national dataset containing the 2, 3, 6 and 8-fold urban rural definitions.  All layers were clipped to both the Mean High Water and Extent of the Realm coastlines.