How were the areas that were monitored for the recent 20mph speed limit change review selected by Transport for Wales?
Transport for Wales (TfW) used the following approach to select the monitoring areas:
1. TfW identified the following set of requirements to ensure a wide variety of areas were selected:
a) A mix of settlement sizes based on population (e.g. settlements >50,000 people as well as smaller settlements c.1000 and population sizes between)
b) A mix of built-up area types from highly urbanised to built-up areas (towns or villages) in a rural setting
c) Geographical spread across Wales
d) Areas that were predominantly 30mph before 17th Sept 2023 and would be predominantly 20mph after 17th Sept
2. TfW then selected settlements from a complete list of built-up areas in Wales (as defined by the OS) and their populations ensuring the above requirements were satisfied.
3. TfW approached transport officers at the local authorities responsible for each area to confirm suitability. The area list was then finalised.
4. TfW identified potential specific monitoring points on main through roads in each area which are largely free from physical restrictions that would otherwise restrict traffic flow (such as extensive traffic calming or parking that restricts flow). This was to ensure that TfW wasn’t going to be monitoring on roads where speeds would be lower anyway regardless of the speed limit.
5. TfW confirmed the specific monitoring points with the local authorities, as a final check that (i) the road would be suitable for free-flowing speed measurements and (ii) the road would be changing from 30mph to 20mph on 17th Sept.