Cycling , walking or driving – what are the risks and benefits ?

1. Cycling, walking or driving – what are the risks and benefits? Dr Jennifer Mindell Clinical senior lecturer Health and Social Surveys Research Group Research Department of Epidemiology & Public Health UCL (University College London)

2. Health benefits of walking and cycling • Health Survey for England 2008: 66% of the adult population (61% men, 71% women) in England were insufficiently active • Walking and cycling: • to work is as effective as a training programme and can fulfil the recommendations for physical activity • can provide the same health benefits as sports or other exercise • can increase cardiorespiratory fitness

3. Health benefits – cardiovascular fitness • Even in men from households with cars, men who walk or cycle to work have a lower rate of death from ischaemic heart disease than men who travel to work by car. • Studies in Denmark, China, and the UK have found substantial reduction in mortality rates in people who cycle regularly. • People who cycle regularly have the explosive muscle power of someone 10years younger. • Oja, Finland: 55-year-old cyclists had the aerobic fitness of people 30 years younger.

4. Benefits of walking and cycling • Activity • Age-independent • Affordable • Access • Air quality • Flexibility • Mental health • Less sick leave • Longevity • Safety in numbers

5. Walking, cycling & the obesity epidemic • Inactivity costs • the NHS £1bn (2007) • society £8bn (2002) • In 2007, obesity cost: • NHS £4bn • society £15bn

6. Trends in obesity and overweight in children (aged 2-15) in England, HSE 1995 – 2011

7. Trends in obesity and overweight in adults (aged 16+) in England, HSE 1993 – 2011

8. Obesity risk • increases by 6% for each hour per day spent in a car • falls by 4.8% for each km walked per day

9. Even in active people • Car commuters in Adelaide, Australia gained more weight over a 4yr study than non-car commuters. The effect was particularly pronounced when comparing those who had sufficient leisure time PA. Sugiyama et al. Am J PrevMed. 2013;44:169–73.

10. ”Incorporating activity such as walking and cycling into daily life is the easiest way to be physically active.” Sir Liam Donaldson, Chief Medical Officer, England 2004

11. Asher L, Aresu M, Faslaschetti E, Mindell JS. Most older pedestrians are unable to cross the road in time: a cross sectional study. Age Aging. 2012;41:690-4. Appleyard, 1981 Daily Mail, 2012 Reproduced by kind permission of Pugh & the Daily Mail

12. Injuries • GB 2011:203,950 road traffic casualties • 11% serious, non-fatal injuries (23,122) • 1,901 fatalities (<1%) • In 2011: • 883 car occupants • 453 pedestrians • 362 motorcyclists • 107 cyclists

13. Who makes the news? • High visibility • Injured cyclists • Low visibility • Patients because inactive • Healthy because active

14. Actual risk for cycling • Risk of death • one per 30,000,000km cycled • Individual risk: one fatality every 20,000 years (assuming typical cyclist rides about 1,500 km pa) • Risk of collision leading to hospital admission: • one per 2,000,000 km cycled • less than one in a thousand annually (1) Department for Transport. Pedal cyclist casualties in reported road accidents: 2008. London: DfT, 2010.

15. Cycling in London The number of people cycling increased by 91% from 2000 to 2009. The proportion of cycling deaths and serious injuries fell by 33%.

16. Problems with existing comparisons • Official comparisons • Different coding for pedestrians and cyclists (falls) • Different treatment of location • Numerator data • Stats 19 Police data • Hospital Episodes Statistics (HES) • Denominator data • National Travel Survey (NTS) • Age / Sex / Socio-economic position (SEP)

17. Cycle safety Risk per year, All ages • UK Drivers: 1 in 30,000 • UK Cyclists: 1 in 23,000 • French drivers: 1 in 10,000

18. Cycle safety Risk per hour for UK drivers and cyclists, 2008 data

19. Aim: To make like-for-like comparisons across travel mode by age and sex

20. Like-for-like comparisons • Denominator data • National Travel Survey • 2007 – 2009, England • By age, sex, travel mode • Per billion km • Per million hours’ use (mhu) (mean speed by mode)

21. Like-for-like comparisons – Numerator data • Mortality data (ONS) • Primary outcome • Hospital admissions (HES data) • Mean LOS after traffic collision: • 2·9d for cyclists • 2.9d for drivers • 4·7d for pedestrians • Specified, comparable, 4 digit ICD-10 external codes (eg W00.4)

22. Results

23. Fatalities (f/mhu) Age-group

24. The risks per hour of the three modes vary within similar ranges, but show different trends with age. Notably, males aged 17-20y faced almost five times greater risk per hour as drivers than as cyclists; but male cyclists 70+ were the most at risk of any group in this study.

25. Fatalities (f/mhu) Age-group

26. Fatalities (f/mhu) Age-group

27. On-highway fatality rates by distance travelled

28. Fatality rates by distance travelled were similar for cyclists and pedestrians when collisions and falls on-highway were included, but were generally an order of magnitude higher than for drivers - except for males aged 17-20y.

29. Comparison of f/mhu in England and The Netherlands

30. Caveats for comparison with Dutch data • 1. Slightly different age groups • 2. Risks in Netherlands (pink) for car users - include passengers, so much lower than for young drivers in England (red) • 3. Similar pattern in older people • 4. Lower risks for cyclists in NL but same order of magnitude; mostly males in England and more females than males in NL; more male drivers in NL

31. Limitations • Accuracy of HES coding • ‘unspecified’ • Use of mean speed by mode • Underestimated denominator • older people • women • Type of road • Ignores impacts on others

32. Relative risk of different forms of transport, Great Britain: 2011 – published statistics Casualty rate per billion vehicle miles Killed Killed or seriously injured • Car driver 3 26 • Pedestrian *42 542 • Pedal cyclist 35 1,035 • Motorcycle rider 122 1,868

33. On-highway fatalities by distance travelled, all ages

34. Comparative risks • Lifetime risk • Road traffic fatality: one in 240 • Cycling one hour every day for 40y: one in 150 (~ average European driver) • Smoking 20 cigarettes/d: one in two • Motorcyclists’ risk >10 times greater than other classes of road user

35. Conclusions (1) • Overall, fatality risk similar for cyclists, pedestrians, and drivers • Risk higher in males than females • Risk for young male drivers not lower than cycling until 20s or 30s • Risks for everyone are lower if young males cycle rather than drive

36. Other recent research • Luoma et al, 2012: Facing the traffic when walking in the road reduced pedestrian injury collisions with motor vehicles by 77% in Finland, 2006-2010. • Jarrett et al, 2012: Increased walking & cycling in urban areas and less use of private cars could save the NHS £17bn (2010 prices) in 20 years, even if road injuries increased. • Davis, 2010, for GOSW: median benefit:cost ratio 19:1 for walking & cycling infrastructure projects • NICE PH guidance 41, Nov 2012.

37. Other recent research: Rolison et al, 2012 • Risk of fatal injury was higher for drivers, passengers and pedestrians aged 70+. • Numbers of drivers aged 70+ killed is small but most passengers and pedestrians killed are 70+ (GB 1989-2009). • Drivers & passengers aged 21-29 also at high risk. • (Those aged 17-20 were not studied)

38. Conclusions (2) • Not making like-for-like comparisons sustains the myth that cycling is relatively hazardous • Benefits of cycling outweigh risks (20:1?) • Professionals have a duty to give unbiased advice Mindell JS, Leslie D, Wardlaw MJ. Exposure-based like-for-like assessment of road safety by travel mode, using routine health data. PLOS One. 2012; 7: e50606. www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0050606

39. Acknowledgements • Co-authors: • Malcolm Wardlaw, Edinburgh, Scotland • Debbie Leslie, Deakin University, Australia • London Health Observatory • Robel Feleke, • Allen Baker, • Ed Klodawski, • DfT NTS team • Gary Smith

40. Transport and health - further reading • Mindell JS, Cohen JM, Watkins S, Tyler N. Synergies between low carbon and healthy transport policies. Proceedings of the Institution of Civil Engineers – Transport. 2011;164:127-39. • Mindell JS, Watkins SJ, Cohen JM (Eds). Health on the Move 2. Policies for health promoting transport. Stockport: Transport and Health Study Group, 2011. ISBN 978-1-61364-769-1 www.transportandhealth.org.uk • and in future: Journal of Transport and Health

41. Risk relative to cycling: fatality rates per participant Figures relate to UK, 1986 and are derived from OPAS Monitors from the Office of Population Censuses and Surveys, UK. The number of fatalities are taken from Coroner's Court records and information on participation rates from the General Household Survey.