20mph Phase 1 - Air Quality Monitoring Report - May 2024


National implementation, data - February 2024

Preliminary weighted mean speed (mph) changes on main through roads following the national 20mph default speed limit on restricted roads

These data are preliminary. Further post-implementation data are being collected during 2024, so post-implementation speeds presented here will be subject to change. For this reason, caution is recommended when interpreting. The data are representative of the areas monitored but may not be representative of all of Wales.

The data were collected on main through roads at 43 locations in nine settlements. All roads monitored had a 30mph speed limit before 17 September 2023 and a 20mph speed limit from 17 September 2023 onwards. All roads were largely free from physical restrictions that reduce traffic speeds at the time of monitoring.


Compliance with the Code of Practise for Statistics:


Default 20mph Speed Limit On Restricted Roads Phase 1 Areas - February 2024


Default 20mph speed limit on restricted roads - September 2023


Default 20mph Speed Limit on Restricted Roads Phase 1 - March 2023

Contact details for this report

Geospatial and Strategic Transport Analysis Unit