National 20 mph speed limits Implementation

As part of the initial national 20 mph speed limit implementation phase road authorities have been considering the introduction of 20 mph speed limits indicated by speed limit signs, with no supporting speed reducing features.

Research has found, implementing sign only using a city/village wide approach may be more effective than implementing limits on specific streets as it encourages a more consistent reduction in speed across a wider area . This approach has demonstrated a higher reduction in speed and may also contribute to changing travel and driving behaviour positively in the longer term.

The use of Temporary Traffic Road Orders (TTRO) to implement 20 mph speed limits, has allowed for progress to be made with implementation, gives the community time to experience the change and for the lower speed limit to be monitored and evaluated over a maximum period of 18 month. During this period, a measured and informed decision can then be made as to whether the 20 mph speed limit can be refined or modified in terms of:

  • Reducing or shifting the extents of the speed limit in length.
  • Considering speed management measures to aid better compliance; or used as an opportunity to implement local plans that are complemented by the lower speed limit, such as active travel measures.
  • Evidencing or accepting that the road is not appropriate and reverting to a speed limit of 30 mph either partially or in full.

In addition, some road authorities have already carried out sufficient assessments and are able to implement 20 mph speed limits on a permanent basis with a Traffic Road Order (TRO).

Ultimately it will be for each road authority to determine which roads on their network should be subject to a 20 mph speed limit and to decide how best to give effect to this by way of orders made under section 84 and section 88 of the Road Traffic Regulation Act 1984 (legislation.gov.uk).