20 MPH study project

This study examines the impact of 20mph speed limits on safety and public health.

Rates of traffic accidents and injuries before and after the change will be measured to look at whether road safety has been enhanced. Any change in transport use will also be scrutinised by examining the take-up of cycling and walking. Residents will also be asked their opinions of the change. It is the largest project of its kind in the UK and will run until 2020.

The research team, led by the University of Edinburgh and SCPHRP, hopes the project will inform other cities planning to introduce lower speed limits. It is the largest of its kind in the UK and will run until 2020. SCPHRP’s Ruth Jepson said: “We are excited about this major project, which we hope will provide very important insights into the public health effects of such initiatives.

Resources Reports and more…

Article in The Edinburgh Reporter: City Council Evaluates Impact of 20mph Zones

An evaluation report has concluded that the Council’s pioneering roll-out of 20mph speed limits across Edinburgh has broadly met the project’s aims and objectives. The report also recommends beginning the process to add further roads to the 20mph network.

Read more.

REPORT: Key outcomes following the implementation of 20mph speed limits in the City of Edinburgh

Dr. Glenna Nightingale and Professor Ruth Jepson on behalf of the NIHR 20mph evaluation project team

September 12th , 2019

This report is prepared by the “Is twenty plenty for health?” project team, based at the University of Edinburgh and several other Universities around the UK. The project team is conducting an evaluation of the public health impact of the 20mph speed limit policies in Edinburgh and Belfast (results not reported here). This project is funded by the NIHR and final results will not be available until after August 2020. The aim of this interim report is to provide an overview of changes in vehicle speed and volume and road traffic collision rates resulting in personal injury before and after the implementation of the 20mph speed limits in Edinburgh. Further analyses will include the use of time series and spatio-temporal models for assessing the trend (temporal and spatial) of road traffic collisions in the City of Edinburgh.

Read the report here.

A short animation about the 20MPH project.

The IT team at the University of East Anglia UEA have developed a short animation explaining the 20mph project. Thanks to Dr Karen Milton for co-ordinating the animation, and to Dr Ruth Hunter for providing the narration


An interview with SCPHRPs Professor Jepson about the project.





The SCPHRP  and Physical Activity for Health Research Centre (PAHRC) project team embarked on a four-day survey to capture the public perception of the planned implementation of 20mph speed limits in zones 4 and 5 by the City of Edinburgh Council.  The survey questions ranged from general knowledge on the 20mph programme to drivers’ attitudes towards the proposed 20mph speed limit.  As a follow-up, this project seeks to measure public perception after implementation of the speed limit.  The results from the survey will be analysed (together with supplementary data from other sources) to accurately portray the impact of the 20mph speed limits in Edinburgh.

For further information please contact Dr Glenna Nightingale at glenna.nightingale@ed.ac.uk.

The study is funded by the National Institute for Health Research and involves partnership with other UK universities, NHS Health Scotland, and the charity Sustrans.

Publication Information
Date of Publication 01/01/1970