1. 20 mph Speed Limits – Public Health Perspective Tom May Public Health Practitioner & Physical Activity Lead Hertfordshire County Council

2. Overview Report Summary from Director of Public Health (Item 2d in papers) Implementation Evidence from Public Health in Bristol Summary of HCC Public Health Directorate Position

3. DPH Interpretation of the Evidence In some areas with high rates of road casualties the evidence is tending to suggest speed limits at 20mph are an intervention which can be effective It won't work in all areas so needs careful consideration of where it will work and where it won't

4. Public Health Interpretation of the Evidence "Mandatory 20 mph zones may be cost- effective in high casualty areas when a CBA from a societal perspective is considered. Although CBA may appear, in principle, more appropriate, the quality, age or absence of reliable data for many parameters means that there is a great deal of uncertainty and the results should be interpreted with caution." - Journal of Public Health in 2013

5. 20 mph 30 mph The risk of fatal injury to adult pedestrians and vehicle impact speed Source: RoSPA – Nov 2012

6. Candidate locations There are several areas in Hertfordshire where the road casualties give some cause for concern, but we would need to determine whether these areas were areas in which a 20mph zone would work

7. Some Findings From Bristol The results showed a small but significant reduction in average daytime speeds in both areas; a 1.4mph reduction in inner south and 0.9mph reduction in inner south. Other headline findings include: 65% of roads saw a reduction in mean speeds; There was no measurable change in air quality or noise; Pedestrian causalities remained constant in both areas; Community support for lower speed limits increased from 70% to 89% after implementation. There was mean of a 23% increase in walking and a 20.5% increase in cycling in the pilot areas

9. Inactivity In Strategic Context £166 M* in Hertfordshire (12-22% burden of this falls on the NHS) per year HWB Strategy – 9 Priorities - Increasing Physical Activity - Healthy Weight - Mental Health * includes benefit payments, sickness benefits, loss of production and loss of taxation revenue due to loss of earning/unemployment

10. 20mph Public Health Position Summary Evidence is not always clear cut but on balance public health support for implementation where appropriate Safety evidence – stronger (where slower speeds are achieved) Cardiovascular health evidence – not as strong but promising A public health approach would suggest considering the intervention in areas it would have greatest impact. Supportive environments can help encourage physical activity

11. Contact Details Tom May  tom.may@hertfordshire.gov.uktom.may@hertfordshire.gov.uk  07771 840275