Essential Evidence for Walking and Cycling

The Cycling City project was informed by a solid basis of evidence about the benefits of cycling and walking, and about what measures encourage more of us us to include them as part of our lives. This page is about some of that evidence.

Two desktop reviews of the academic evidence were compiled in 2008.  Dr Adrian Davis is a specialist in Transport and Health and produced What Works to get more people cycling, while Professor Alan Tapp works in the field of social marketing, that is how to use and understanding marketing for social ends, and produced What Works for social marketing of cycling. Their reports are in the downloads section below.

Dr Adrian Davis has been publishing a weekly series of 'Essential Evidence on a Page' where he sumarises key papers and issues around transport and health. The top lines of these reports are listed below.

Key sites for information: 

• Department for Transport (Cycling England)
• Sustrans - Evidence for walking, cycling and health
• CTC - Resources and Policy
• Transport for London design standards
• Bath and North East Somerset Council
• Bristol City Council
• North Somerset Council
• South Gloucestershire Council

Other links to useful resources:

• At the Frontiers of Cycling: Policy Innovations in the Netherlands, Denmark, and Germany (a version of this paper is also called 'Making Cycling Irresistable' and is a recommended online lecture)
• Cycling and the Law
• Cycle Infrastructure Design LTN 2/08 - how to build infrastructure that works

Essential evidence - the benefits of cycling and walking

Key evidence from peer-reviewed literature, often from a public health evidence base is being used to strengthen the case for current policies and practice. These papers are published on the Bristol City Council website. The most relevant and useful for cycling are highlighted with an asterix *.

1. Safety in numbers *
   Risk of injury decreases as rates of walking and cycling increase. Motorists appear to adjust their behaviour in the presence of people walking and cycling which largely controls the likelihood of collisions.
2. Segmentation in behaviour change *
   Different psychographic groups can be identified with varying degrees of mode switching potential. Each group represents a unique combination of preferences, worldviews and attitudes, indicating that different groups need to be serviced in different ways to optimise the chance of influencing mode choice behaviour.
3. Evidence hierarchy
   Some types of study are more robust and valuable that others for answering particular types of question.
4. Cycling and all cause mortality *
   Regular cyclists are likely to have a lower risk of death compared to non-cyclists, irrespective of other physical activity they do.
5. Impact of highway traffic capacity reductions *
   Traffic appears to ‘disappear’ in response to reductions in road capacity, but only to the extent that it needs to do so. The impact of capacity reduction is rarely more intense than the already endemically bad levels of congestion that many towns experience.
6. Walking to health
   Walking is the nearest activity to perfect exercise. Regular walking reduces the risk of cardiovascular and respiratory diseases, type 2 diabetes, some cancers, deaths from all causes, and helps to counter depression and maintain mental wellbeing.
7. Weight gain and car use
   Time spent in cars increases risk of weight gain in contrast to time spent using active travel modes. Purchase of motorcycles or cars to travel to work has been reported as doubling the likelihood of becoming overweight.
8. Physical activity - the best buy in public health
   There is a significant role for transport planning through the provision of walking and cycling-friendly infrastructure and behaviour change programmes to help raise total physical activity levels and so contribute to overall public health.
9. Bus use and deregulation
   Public transport subsidy in South Yorkshire benefited the health of the local population by providing the social amenity of additional travel at the least additional health cost. df
10. Cycle commuting *
    Regular cyclists are as fit as non-cyclists 10 years younger. Non-exercisers taking up cycling get benefits quickly and the more they cycle, the fitter they become.
11. Walkable communities
    There is strong evidence that social networks and community involvement have positive health consequences and this is encouraged in walkable, mixed-use neighborhood designs.
12. Life change events and physical activity participation *
    Life changes affect participation in physical activity. Awareness of these may help to increase effective targeting for travel behaviour change interventions drawing on these life change ‘stages’: employment; residence; health; relationships; family structure.
13. Cycling reduces absenteeism at the workplace *
    Employees regularly cycling to work are ill less often. Regular cycling commuters missed on average 15% fewer days than non-cyclists.
14. A healthy school journey *
    Improving the modal share of walking and cycling among children is strongly associated with reducing motor traffic speeds along routes to schools.
15. Vision Zero
    Lowering speed limits in urban areas in Sweden has reduced injuries to cyclists and pedestrians by 50 percent.
16. Objective monitoring, children's travel and physical fitness
    Increased emphasis on improving the physical and built environment, and addressing parental concerns about children’s safety, are important determinants of children’s physical activity and fitness levels.
17. Using pedometers to increase physical activity and improve health
    There is strong evidence that pedometer users increase steps taken by an average of over 2000 steps more than among those not using pedometers.
18. The role of habit in travel behaviour *
    Personalised journey planning can increase awareness of alternative modes to car use and change travel behaviour even among those with a strong car habit.
19. Unintended health impacts of road transport policies and interventions *
    Transport interventions have important potential impacts on health and health inequalities and these need to be better understood by policy makers and practitioners if unintended harm is not to be inflicted on population or sub-population groups.
20. Health Impact Assessment (HIA)
    HIA can be a useful tool whereby health impacts of policies, programmes and interventions and their distribution across the population can be assessed in order to enhance positive and reduce negative health impacts identified.
21. Obtaining a driving licence and interventions to influence the decision *
    Information supplied to young adults about negative aspects of car use before a driving license is acquired may have a positive impact on their mode use, at least in the short term.
22. Inverse Care Law *
    The frequency with which parents advocate for child safety varies inversely with the need for it. Models of health promotion based on community ownership and empowerment alone are unlikely to address the steep socioeconomic gradients in childhood injury mortality.
23. Mass Community Cycling Events 
    While the public health evidence base as to the effectiveness of mass cycle rides is limited, in this study participants who were novice riders or first time participants significantly increased their number of bicycle rides in the month after the event.
24. Economic Benefits of Cycling *
    Economic analysis of cycling interventions suggests that average benefit per additional cyclist is £590 per year, and that small increases in cycling numbers can justify investment in new cycling infrastructure principally due to the health benefits which accrue.
25. Cycling Safety - Lessons from The Netherlands, Denmark and Germany *
    Evidence from countries with high cycling levels suggests that the key is the provision of separate cycling facilities along heavily travelled roads and at intersections, combined with residential street traffic calming.
26. Effect of crime and neighbourhood on physical activity
    Feeling safe during both day and night potentially has the largest effect on population levels of physical activity.
27. Air Pollution
    Road transport is the chief source of the emissions responsible for respiratory related deaths in England. Reducing particulate emissions from motor vehicles could significantly reduce the number of such deaths.
28. Public transport and physical activity
    Population-level efforts to increase non-leisure physical activity, particularly active transport, are sorely needed as a means of help promote and maintain active lifestyles. Walking to and from public transport stops can help physically inactive populations attain the recommended level of daily physical activity.
29. Illness arising from road transport 
    Transport strategy and guidance requires a greater understanding of the range of health impacts arising from transport in order to deliver a sustainable transport system. The public health evidence base can help inform both national and local strategies.
30. Cost benefit analysis of walking and cycle track networks *
    Investment in walking and cycle track networks in three Norwegian cities seems to be highly beneficial to society since net benefit/cost ratios in these cities were approximately 4:1, 14:1 and 3:1, respectively (ie highly positive).
31. Walk in to Work Out
    A high quality intervention study has showed that self help materials can increase walking to and from work. Twenty five per cent of the initial intervention group, who were contemplating or preparing to actively commute at baseline, were regularly walking to work one year post intervention.
32. NICE Guidance *
    The guidance offers the first NICE evidence-based recommendations on how to improve the physical environment to encourage physical activity. Specific recommendations are addressed to those working within the transport planning sector.
33. Assessment of the Active for Life Campaign
    Increasing physical activity levels is a long-term task. Short-term promotional programmes encouraging behaviour change may be insufficient. Broader policy and environmental changes to support physical activity are likely to be required.
34. Evidence led policy or the art ofthe possible?
    Evidence-base guidance can be welcomed but also viewed as a threat to the existing world view. Separately, working out how to handle divergent evidence is as important a task as gathering more evidence. Transport planning is not immune to such tensions.
35. Urban Environment *
    Tackling urban environment problems not only benefits the environment, but improves the health and wellbeing of citizens and should be seen as central to economic viability by making towns and cities more attractive places to live and work
36. Children's independent mobility *
    Independent mobility appears to be an important independent determinant of weekday physical activity for both boys and girls.
37. Impact of retirement on physical activity *
    Public health and other sector initiatives (eg transport) that encourage people to become more physically active should be targeted at those who are about to retire.
38. Women and commuter cycling *
    Improved cycling infrastructure through bicycle paths and lanes that provide a high degree of separation from motor traffic is likely to be important for increasing transportation cycling amongst under-represented population groups such as women.
39. Social Patterning
    A key issue in reducing health inequalities is a reduction of physical and social barriers to everyday opportunities for physical activities in people’s local environments.
40. Effect of driving cessation on the elderly
    As the population ages and lifespan increases, disabling conditions affecting elders will require transport solutions which both enables them to maintain a minimum acceptable level of accessibility but which are not so reliant on informal family care and potential negative effects on the health and wellbeing of informal care providers.
41. The importance of “walkable” green spaces
    Neighbourhood green environments where people can walk are likely to contribute to residents’ physical and mental health. In order to promote community health through enhancement of the environment, the planning and design of neighbourhood open spaces need to emphasise the importance of “walkable” green spaces.
42. A convenient truth: Climate change mitigation from transport is good for health *
    It is a ‘convenient truth’ that climate mitigating interventions are health beneficial. Reduction in transport-related greenhouse-gas emissions and increases in distances walked and cycled could have important health benefits.
43. Child physical activity and effect on body weight
    Public health policies to reduce obesity in children should include strategies to promote higher levels of physical activity, particularly activity that is of moderate intensity and above. The school journey is a key means by which children can achieve the recommended level of at least 1 hour of physical activity per day.
44. Electrically assisted Cycling *
    The intensity of physical effort during cycling on an electrically assisted bicycle is sufficiently high to contribute to the physical activity guidelines for moderate-intensity health-enhancing physical activity for adults.
45. Effective interventions to increase cycle use *
    Substantial increases in bicycling require an integrated package of many different, complementary interventions, including infrastructure provision and pro-bicycle programmes, supportive land use planning, and restrictions on car use.
46. Use of non-motorised modes and life stages
    Utilisation of a life-stage approach to travel behaviour change identifies groups which may be most effectively targeted in increasing use of non-motorised travel modes.
47. Stairs instead of escalators
    Motivational posters to encourage stair use rather than escalators have been shown to be effective in increasing stair use. There is some evidence that males respond more positively to such messages than females.
48. Attitude-based targeting of mobility types for mode shift
    Identifying differing mobility types can assist in the task of delivering modal shift through selecting and preparing targeted information for the different mobility types.
49. Food deserts
    The assumption that in the United Kingdom there are poor urban areas where residents cannot buy affordable, healthy food (“food deserts”) and that this is a widespread problem is not well supported by the evidence. Overall, retail interventions may have either a small but important effect or no effect on diet and health.
50. Peak Oil
    The city regions that will prosper this century will be those that successfully adapt their approach to transport. Within densely populated areas the normal choice will be safe, reliable, comfortable and affordable public transport combined with walking and cycling.
51. The Precautionary Principle
    Risks to health in the 21st century are increasingly likely to come as a result of global threats to resources. A precautionary approach, especially around resilience, notably protecting finite resources, is a highly rational approach in such a period of uncertainty from potential major threats.
52. Is speeding a "real" antisocial behaviour? *
    Speeding traffic is rated as the greatest antisocial behavior in local communities. On the basis of results reported in the British Crime Survey police could argue that any enforcement programme currently operating is compatible with public concern.
53. Perceived barriers to public engagement with climate change
    There is a need for UK policies and governance structures to initiate a systemic shift to a low consumption paradigm in order to move people out of their comfort zone of carbon-intensive living. Such a shift would have additional benefits, including fostering
    social justice and well-being, aside from climate change mitigation.
54. Health effects of a neighbourhood traffic calming scheme *
    Traffic calming schemes are not only beneficial through casualty reduction and in reducing traffic danger but may also be important in improving physical health status among local residents.
55. Casualty and Road Danger Reduction *
    In an era when there is greater collective agreement than previously as to the need to promote walking and cycling, a change in emphasis in road safety is required, with a redeployment of resources towards tackling the sources of danger, rather than just looking at those groups who are the victims.
56. Children's physical activity and academic performance
    There is a significant positive relationship between physical activity, improved cognitive performance and academic achievement. This conclusion provides evidence for the argument that physical activity should be part of the school day for both its physical health and cognitive benefits. The physically active school journey can therefore contribute significantly to broader educational goals.
57. Community severance barrier effect *
    Certain population groups are especially adversely affected by motor traffic acting as a barrier to them accessing local facilities on foot. Understanding the barrier effect is an important consideration for transport planning, not least when promoting walking as transport.
58. Car use weight gain and carbon
    The leading cause of adult obesity is a major decline in physical activity. The substitution of walking by car use is having a major impact on adult body weight and carbon emissions. A return to higher levels of walking would help improve human and planetary health.
59. Global perspective on urban health
    By providing better accessibility to all, sustainable transport can have direct benefits in terms of poverty reduction. Healthier transport can spread the health and environment costs and benefits of transport more evenly across the population sectors.
60. Childhood asthma and traffic pollution
    Research has found a possible link between traffic-related air pollution outside people’s homes and the onset of asthma in children during the first eight years of life. Higher levels of nitrogen dioxide, PM2.5 and soot (generated by greater traffic volumes) were more likely to be recorded at the homes of those children who developed asthma and asthma symptoms.
61. Doorstep walks
    While interventions to promote walking are at risk of largely being taken by the already active there is evidence that it is possible through a targeted distribution of information to stimulate an increase in walking among those previously sedentary.
62. ‘Nudge’: Normative social influences on behaviour change *
    Research suggests that normative information is a powerful but undetected form of social influence. Although people may not believe that the behaviours of others should motivate them to change their behaviours, such as to conserve energy, their behaviour is powerfully influenced by it nonetheless.
63. Dose response to physical activity
    There is a relationship between the amount of physical activity, disease risk and premature death. In short, even a little physical activity is good; more is better.
64. The common cold, physical activity and immune function
    Physical fitness and physical activity are strongly linked with lower risk of ill-health from infections such as the common cold. Walking and cycling, as routine physical activities, provide increased protection against such causes of ill-health through enhanced immune function.
65. Physical activity, walking, and the prevention of falls
    The risk of increasing falls among a largely sedentary older population can be reduced through physical activity. Walking, as the most readily available physical activity, can contribute to the prevention of falls through maintaining or increasing leg muscle and bone strength.
66. Public Health White Paper 2010
    Public health’s return to local government provides a major opportunity to provide more integrated services where improved health as an outcome is embedded within service ethos and delivery.
67. Speed of drivers in presence of child pedestrians *
    One significant contributor to crashes involving child pedestrians is vehicle speed. Issuing specific guidelines about appropriate speeds, drawing drivers’ attention to the discrepancy between their beliefs and behaviours and enforcing the actual speed limit in the presence of child pedestrians are potentially promising strategies.
68. Spend on high streets according to travel mode *
    Government has recognised the evidence that pedestrians, cycle and public transport users provide as much if not more spending power than car users in town centres. This supports the case for investment in active and low carbon travel in retail areas and corrects a common misconception.
69. Non-cycling adults - how to engage them in cycling
    There are people for whom cycling is attractive and possible due to bicycle ownership but who have yet to take up this mode or with any regularity. Targeting young adults and those in higher social income groups appears to offer an effective means, in the short-term, to attract new cyclists. Some of these will previously have travelled by car.
70. Exercise at work and self-reported work performance
    Positive changes in self-reported performance outcomes of white-collar employees are mostly linked to the mood changes brought about by exercise. 

 For a full up to date list see Essential Evidence on a Page on the Bristol City Council site.

Downloads: 

A rapid desk-top review of interventions which increase the number of people cycling - Adrian Davis 2008

Social Marketing and Cycling - What Works & What Might Work - Alan Tapp 2008