Background Prevention, rather than treatment, is the key to longer healthier lives. Identifying interventions that will impact positively on road traffic injuries, air quality and encourage active travel is a significant public health challenge. This paper aimed to explore whether 20 mph limits could be useful in achieving this.
Methods Research evidence was reviewed to identify the effect of 20 mph zones and limits on health and well-being. The evidence was then used to estimate the effect of a change to a 20 mph limit on road traffic casualties and air pollution. It was then mapped against the seven goals of the Well-being of Future Generations Act (2015).
Results If all current 30 mph limit roads in Wales became 20 mph limits, it is estimated that 6–10 lives would be saved and 1200–2000 casualties avoided each year, at a value of prevention of £58M–£94M. In terms of air pollution, deaths attributed to nitrogen dioxide (NO2) may increase by 63, and years of life lost by 753. However, deaths attributed to particulates (PM2.5) may decrease by 117 and years of life lost by 1400. Evidence review suggests benefits in terms of road traffic casualties, air quality, active travel, noise pollution, greater social inclusion, greater community cohesion and local business viability.
Conclusions Road traffic injuries, air pollution and obesity are an inter-related, interdependent triad. The challenge facing public health today is identifying robust interventions that will have positive effects on all three as a minimum; default 20 mph limits is the solution to increasing public health problems in Wales.
- PUBLIC HEALTH POLICY
- AIR POLLUTION
- ENVIRONMENTAL HEALTH
1. Lopez A, Mathers C, Ezzati M, Jamison D, Murray C. Global and regional burden of disease and risk factors, 2001: systematic analysis of population health data. Lancet 2006;367:1747-57. [PubMed]
2. Mathers CD, Loncar D. Projections of global mortality and burden of disease from 2002 to 2030. PLoS Med 2006;3:e442. [PMC free article][PubMed]
3. Hyder AA, Peden M. Inequality and road-traffic injuries: call for action. Lancet 2003;362:2034-5. [PubMed]
4. Cook CC, Duncan T, Jitsuchon S, Sharma A, Guobao W. Assessing the impact of transport and energy infrastructure on poverty reduction. Asian Development Bank, 2005.
5. Hyder AA, Ghaffar A. The millennium development goals and road traffic injuries: exploring the linkages in South Asia. J Coll Physicians Surg Pak 2004;14:742-5. [PubMed]
6. Bannister D, Wright L. The role of transport in supporting sub-national development. Department for International Development, 2005.
7. Department for Transport. Road casualties Great Britain 2006. Stationery Office, 2007.
8. Department for Transport. Tomorrow’s roads: safer for everyone. Department for Transport, 2000.
9. Aarts L, van Schagen I. Driving speed and the risk of road crashes: a review. Accid Anal Prev 2006;38:215-24. [PubMed]
10. Bunn F, Collier T, Frost C, Ker K, Steinbach R, Roberts I, et al. Area-wide traffic calming for preventing traffic related injuries. Cochrane Database Syst Rev 2009;(4):CD003110. [PubMed]
11. Elvik R. Area-wide urban traffic calming schemes: a meta-analysis of safety effects. Accid Anal Prev 2001;33:327-36. [PubMed]
12. Webster D, Layfield R. Review of 20 mph zones in London boroughs. Transport for London, 2003. (project report PPR243).
13. Grundy C, Steinbach R, Edwards P, Wilkinson P, Green J. 20 mph zones and road safety in London: a report to the London Road Safety Unit. London School of Hygiene and Tropical Medicine, 2008.
14. Ward H, Lyons R, Thoreau R. Under-reporting of road casualties—phase 1. Department for Transport, 2006. (Road safety research report No 69).
15. Persaud B, Lyon C. Empirical Bayes before-after safety studies: lessons learned from two decades of experience and future directions. Accid Anal Prev 2007;39:546-55. [PubMed]
16. Bunn F, Collier T, Frost C, Ker K, Roberts I, Wentz R. Traffic calming for the prevention of road traffic injuries: systematic review and meta-analysis. Inj Prev 2003;9:200-4. [PMC free article][PubMed]