20 mph speed limits – public health perspective tom may public health practitioner & physical...

20 mph Speed Limits – Public Health Perspective

Tom MayPublic Health Practitioner & Physical Activity LeadHertfordshire County Council

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

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

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

20 mph

30 mph

The risk of fatal injury to adult pedestrians and vehicle impact speed

Source: RoSPA – Nov 2012

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

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

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

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

Contact Details

Tom May

tom.may@hertfordshire.gov.uk

07771 840275