Research shows benefits of 20mph with 'physical measures'

Fresh research from the Parliamentary Office of Science and Technology (POST) shows that 20mph speed limits supported by physical measures help reduce traffic collisions and casualties.

This is contrasted against 20mph limits based on signage alone, which have been shown to be less reliable due to a lack of enforcement or supporting design changes.

As well as injury reduction, the report highlights wider public health benefits. These include:

• increases in the number of people making journey via active travel, especially when combined with wider public realm improvements;
• Lower vehicle speeds, particularly in 20mph zones;
• Improved public perception, especially where benefits are effectively communicated;
• Potential to reduce health inequalities, although more robust, equity-focused evaluations are needed.

It also emphasises that successful interventions should be multi-faceted, combining infrastructure changes, communication and enforcement.

The research by POST is also supported by the Parliamentary Advisory Council for Transport Safety (PACTS) report on Lower Urban Speed Limits in Europe (LUSTRE) published in 2023.

The new POST publication, which PACTS vice chair Teresa Ciano and deputy executive director Margaret Winchcomb contributed to, can be found here.

Image credit: Shutterstock @William Barton