Studies on Bikeability in a Metropolitan Area Using the Active Commuting Route Environment Scale (ACRES)

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Örebro Studies in Sport Sciences 13

LINA WAHLGREN

Studies on Bikeability in a Metropolitan Area Using the Active Commuting Route Environment Scale (ACRES)

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Örebro Studies in Sport Sciences 13

LINA WAHLGREN

Studies on Bikeability in a Metropolitan Area Using the Active Commuting Route Environment Scale (ACRES)

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Title: Studies on Bikeability in a Metropolitan Area Using the Active Commuting Route Environment Scale (ACRES).

Publisher: Örebro University 2011 www.publications.oru.se

trycksaker@oru.se

Print: Ineko, Kållered 09/2011 ISSN 1654-7535 ISBN 978-91-7668-815-1

Abstract

Lina Wahlgren (2011): Studies on Bikeability in a Metropolitan Area Using the Active Commuting Route Environment Scale (ACRES). Örebro Studies in Sport Sciences 13, 131 pp.

Background: The Active Commuting Route Environment Scale (ACRES) was developed to study active commuters’ perceptions of their route environments. The overall aims were to assess the measuring properties of the ACRES and study active bicycle commut- ers’ perceptions of their commuting route environments. Methods: Advertisement- and street-recruited bicycle commuters from Greater Stockholm, Sweden, responded to the ACRES. Expected differences between inner urban and suburban route environments were used to assess criterion-related validity, together with ratings from an assembled expert panel as well as existing objective measures. Reliability was assessed as test-retest reproducibility. Comparisons of ratings between advertisement- and street-recruited participants were used for assessments of representativity. Ratings of inner urban and suburban route environments were used to evaluate commuting route environment profiles. Simultaneous multiple linear regression analyses were used to assess the relation between the outcome variable: whether the route environment hinders or stimulates bicycle-commuting and environmental predictors, such as levels of exhaust fumes, speeds of traffic and greenery, in inner urban areas. Results: The ACRES was characterized by considerable criterion-related validity and reasonable test-retest reproducibility. There was a good correspondence between the advertisement- and street-recruited participants’

ratings. Distinct differences in commuting route environment profiles between the inner urban and suburban areas were noted. Suburban route environments were rated as safer and more stimulating for bicycle-commuting. Beautiful, green and safe route environments seem to be, independently of each other, stimulating factors for bicycle-commuting in inner urban areas. On the other hand, high levels of exhaust fumes and traffic conges- tion, as well as low ‘directness’ of the route, seem to be hindering factors. Conclusions:

The ACRES is useful for assessing bicyclists’ perceptions of their route environments. A number of environmental factors related to the route appear to be stimulating or hindering for bicycle commuting. The overall results demonstrate a complex research area at the beginning of exploration.

Keywords: active transport, bicycle commuting, bikeability, multiple linear regression analysis, perception, reliability, route environment, validity.

Lina Wahlgren, School of Health and Medical Sciences

Örebro University, SE-701 82 Örebro, Sweden, e-mail: lina.wahlgren@gih.se

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Title: Studies on Bikeability in a Metropolitan Area Using the Active Commuting Route Environment Scale (ACRES).

Publisher: Örebro University 2011 www.publications.oru.se

trycksaker@oru.se

Print: Ineko, Kållered 09/2011 ISSN 1654-7535 ISBN 978-91-7668-815-1

Abstract

Lina Wahlgren (2011): Studies on Bikeability in a Metropolitan Area Using the Active Commuting Route Environment Scale (ACRES). Örebro Studies in Sport Sciences 13, 131 pp.

Background: The Active Commuting Route Environment Scale (ACRES) was developed to study active commuters’ perceptions of their route environments. The overall aims were to assess the measuring properties of the ACRES and study active bicycle commut- ers’ perceptions of their commuting route environments. Methods: Advertisement- and street-recruited bicycle commuters from Greater Stockholm, Sweden, responded to the ACRES. Expected differences between inner urban and suburban route environments were used to assess criterion-related validity, together with ratings from an assembled expert panel as well as existing objective measures. Reliability was assessed as test-retest reproducibility. Comparisons of ratings between advertisement- and street-recruited participants were used for assessments of representativity. Ratings of inner urban and suburban route environments were used to evaluate commuting route environment profiles. Simultaneous multiple linear regression analyses were used to assess the relation between the outcome variable: whether the route environment hinders or stimulates bicycle-commuting and environmental predictors, such as levels of exhaust fumes, speeds of traffic and greenery, in inner urban areas. Results: The ACRES was characterized by considerable criterion-related validity and reasonable test-retest reproducibility. There was a good correspondence between the advertisement- and street-recruited participants’

ratings. Distinct differences in commuting route environment profiles between the inner urban and suburban areas were noted. Suburban route environments were rated as safer and more stimulating for bicycle-commuting. Beautiful, green and safe route environments seem to be, independently of each other, stimulating factors for bicycle-commuting in inner urban areas. On the other hand, high levels of exhaust fumes and traffic conges- tion, as well as low ‘directness’ of the route, seem to be hindering factors. Conclusions:

The ACRES is useful for assessing bicyclists’ perceptions of their route environments. A number of environmental factors related to the route appear to be stimulating or hindering for bicycle commuting. The overall results demonstrate a complex research area at the beginning of exploration.

Keywords: active transport, bicycle commuting, bikeability, multiple linear regression analysis, perception, reliability, route environment, validity.

Lina Wahlgren, School of Health and Medical Sciences

Örebro University, SE-701 82 Örebro, Sweden, e-mail: lina.wahlgren@gih.se

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List of papers

I. Wahlgren, L., Stigell, E. & Schantz, P. (2010). The active commuting route environment scale (ACRES): development and evalua- tion. International Journal of Behavioral Nutrition and Physical Activity. 7:58.

II. Wahlgren, L. & Schantz, P. (2011). Bikeability and methodological issues using the active commuting route environment scale (ACRES) in a metropolitan setting. BMC Medical Research Meth- odology. 11:6.

III. Wahlgren, L. & Schantz, P. Exploring bikeability in a metropolitan setting: stimulating and hindering factors in commuting route environments. Submitted manuscript.

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List of papers

I. Wahlgren, L., Stigell, E. & Schantz, P. (2010). The active commuting route environment scale (ACRES): development and evalua- tion. International Journal of Behavioral Nutrition and Physical Activity. 7:58.

II. Wahlgren, L. & Schantz, P. (2011). Bikeability and methodological issues using the active commuting route environment scale (ACRES) in a metropolitan setting. BMC Medical Research Meth- odology. 11:6.

III. Wahlgren, L. & Schantz, P. Exploring bikeability in a metropolitan setting: stimulating and hindering factors in commuting route environments. Submitted manuscript.

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1 Preface

After taking my degree in Health Science and Health Education at the Stockholm University College of Physical Education and Sports, now named GIH – The Swedish School of Sport and Health Sciences, located in Stockholm, Sweden, I started an additional course in research methodology at the University College. The head of the course was Professor Ingemar Wedman. The meeting with Ingemar became the beginning of my ‘PhD journey’. I first became Ingemar’s project assistant and later, in 2006, a PhD student with Ingemar as my supervisor. My work as a PhD student was focused on questionnaires measuring health, particularly measuring physical activity as a part of health.

In 2007 Ingemar fell ill and in February 2008 he passed away. He did not just leave me with sorrow and emptiness – still I often think of you, miss your cheerful voice and our talks about research – I also had to find a new supervisor.

At GIH – The Swedish School of Sport and Health Sciences, there is a group called the Research Unit for Movement, Health and Environment aimed at exploring the relations between physical activity, public health and sustainable development. Its main research focus is on active commuting. One of the challenges working with physical activity and health is to activate people. An area that I had found interesting was the incorporation of physical activity into normal and habitual daily living. Active commuting constitutes a part of that area. Therefore, after being invited by the head of the research unit, Associate Professor Peter Schantz, I decided to join the group and Peter became my new supervisor. I was offered to work with their main research project named Physically Active Commuting in Greater Stockholm (PACS) and data collected with the aim of understanding more about active commuters’ route environments. For the collection of data, a scale had been developed, called the Active Commuting Route Environment Scale (ACRES). Before exploring factors of possibly importance in the commuting route environments, I had to begin exploring the accuracy of the ACRES. This became my new research focus as a PhD student, and consequently the beginning of this thesis.

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1 Preface

After taking my degree in Health Science and Health Education at the Stockholm University College of Physical Education and Sports, now named GIH – The Swedish School of Sport and Health Sciences, located in Stockholm, Sweden, I started an additional course in research methodology at the University College. The head of the course was Professor Ingemar Wedman. The meeting with Ingemar became the beginning of my ‘PhD journey’. I first became Ingemar’s project assistant and later, in 2006, a PhD student with Ingemar as my supervisor. My work as a PhD student was focused on questionnaires measuring health, particularly measuring physical activity as a part of health.

In 2007 Ingemar fell ill and in February 2008 he passed away. He did not just leave me with sorrow and emptiness – still I often think of you, miss your cheerful voice and our talks about research – I also had to find a new supervisor.

At GIH – The Swedish School of Sport and Health Sciences, there is a group called the Research Unit for Movement, Health and Environment aimed at exploring the relations between physical activity, public health and sustainable development. Its main research focus is on active commuting. One of the challenges working with physical activity and health is to activate people. An area that I had found interesting was the incorporation of physical activity into normal and habitual daily living. Active commuting constitutes a part of that area. Therefore, after being invited by the head of the research unit, Associate Professor Peter Schantz, I decided to join the group and Peter became my new supervisor. I was offered to work with their main research project named Physically Active Commuting in Greater Stockholm (PACS) and data collected with the aim of understanding more about active commuters’ route environments. For the collection of data, a scale had been developed, called the Active Commuting Route Environment Scale (ACRES). Before exploring factors of possibly importance in the commuting route environments, I had to begin exploring the accuracy of the ACRES. This became my new research focus as a PhD student, and consequently the beginning of this thesis.

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2 Background

This thesis presents a novel methodological design for studying people’s perceptions of environmental factors in their active commuting route environments. The overall aim is to understand which factors can be of importance for creating a stimulating route environment for bicycle commuting.

The aim of the following Background segments is to present the context in which this thesis has evolved.

2.1 Physical activity

Historically, physical activity has been a natural part of being a human being. Nearly all types of human work required a physical effort, not least movement. In contrast, the last few centuries’ ‘labour-saving devices’ in the industrialized world have resulted in the common lifestyles of inactivity.

For example, people predominantly transport themselves by motorized means. People’s physical inactivity is a public health concern because physical activity has many substantial health benefits (cf., e.g. U.S. De- partment of Health and Human Services, 2008). Parts of the populations in various countries do not meet the recommended level of physical activity (cf., e.g. Bauman, Bull, Chey et al., 2009). For example, although difficult to estimate, about one third of the Swedish adult population do not meet the recommended minimum level (cf. The National Board of Health and Welfare, Sweden, 2009). Increasing the level of physical activity in the population is therefore an important public health goal (e.g. World Health Organisation, 2004).

Physical activity can be defined as ‘any bodily movement produced by skeletal muscles that result in energy expenditure’ (Caspersen, Powell and Christenson, 1985, p. 126). Furthermore, physical activity can be broken down into different types, such as walking or swimming, and can be performed with a specific purpose, such as exercise or leisure. The purposes can be combined. For example, the purpose of active transport can be both exercise and transport. Physical activity performed with the purpose of active transport can be further specified by the purpose or the destination of the trip (Figure 1).

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2 Background

This thesis presents a novel methodological design for studying people’s perceptions of environmental factors in their active commuting route environments. The overall aim is to understand which factors can be of importance for creating a stimulating route environment for bicycle commuting.

The aim of the following Background segments is to present the context in which this thesis has evolved.

2.1 Physical activity

Historically, physical activity has been a natural part of being a human being. Nearly all types of human work required a physical effort, not least movement. In contrast, the last few centuries’ ‘labour-saving devices’ in the industrialized world have resulted in the common lifestyles of inactivity.

For example, people predominantly transport themselves by motorized means. People’s physical inactivity is a public health concern because physical activity has many substantial health benefits (cf., e.g. U.S. De- partment of Health and Human Services, 2008). Parts of the populations in various countries do not meet the recommended level of physical activity (cf., e.g. Bauman, Bull, Chey et al., 2009). For example, although difficult to estimate, about one third of the Swedish adult population do not meet the recommended minimum level (cf. The National Board of Health and Welfare, Sweden, 2009). Increasing the level of physical activity in the population is therefore an important public health goal (e.g. World Health Organisation, 2004).

Physical activity can be defined as ‘any bodily movement produced by skeletal muscles that result in energy expenditure’ (Caspersen, Powell and Christenson, 1985, p. 126). Furthermore, physical activity can be broken down into different types, such as walking or swimming, and can be performed with a specific purpose, such as exercise or leisure. The purposes can be combined. For example, the purpose of active transport can be both exercise and transport. Physical activity performed with the purpose of active transport can be further specified by the purpose or the destination of the trip (Figure 1).

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Figure 1. Physical activity specified by type and purpose.

The common view regarding the public recommendation for health- enhancing physical activity (HEPA) (Oja and Borms, 2004) is that people should accumulate at least 30 minutes of physical activity of at least moderate intensity on preferably all days of the week (Haskell, Lee, Pate et al., 2007; Pate, Pratt, Blair et al., 1995; Professional Associations for Physical Activity, Sweden 2003; 2008; U.S. Department of Health and Human Ser- vices, 1996; 2008). Moreover, a physically active lifestyle has been urged (Haskell et al., 2007). A physically active lifestyle or active living represents the incorporation of physical activity into normal and habitual daily living.

Thus, active transport – travelling by, e.g. foot or bicycle – could have an important potential for increasing people’s physical activity level (for a review, see Shephard, 2008) and thereby meeting the physical activity recommendation.

2.1.1 Active transport

Active transport or non-motorized travel, includes walking, bicycling, small-wheeled transports, such as inline skates and skateboards, and wheelchairs (Committee on Physical Activity, Health, Transportation and Land Use, 2005). The most common forms are walking and bicycling.

Active transport, i.e. walking and bicycling, has, however, generally de- clined in the industrialized world over the last decades (cf. Pucher and Buehler, 2010). Active transport and active commuting to the place of work have, from a theoretical point of view, the potential to influence public health positively – especially bicycle commuting, since it seems easier to meet the requested intensity level by bicycle compared to by foot (cf.

Shephard, 2008). Bicycle commuting could probably result in approxi- mately the same improvement in physical performance as specific training programmes (Hendriksen, Zuiderveld, Kemper et al., 2000). An associa-

Physical

activity Type

Walking Bicycling Other

- e.g. swimming, skating

Purpose Recreation Exercise Competition Transport Other

- e.g. household activities, occupa- tional activities

Purpose (destination) WorkOther - e.g. shop, bank

tion between active commuting and reduced cardiovascular risk has been recognized (for a meta-analytic review, see Hamer and Chida, 2008). A Swedish study (Lindström, 2008) demonstrated that active commuting to the place of work had a negative association with overweight and obesity.

Furthermore, transport bicycling and bicycle commuting have resulted in reduced all-cause mortality (Andersen, Schnohr, Schroll et al., 2000; Mat- thews, Jurj, Shu et al., 2007). Although more evidence is needed, regular bicycling will most likely have an impact on health, which will probably affect public health positively (for a systematic review, see Oja, Titze, Bauman et al., 2011). In conclusion, it seems that active transport has the potential to influence health positively.

Besides the likely health benefits, active transports also have other advantages, as well as disadvantages. Active transport could contribute fa- vourably to sustainable development and reduce noise and congestion levels. Active transport is, furthermore, less expensive than other means of transport and is ‘trustworthy’ and represents ‘freedom’ since it does not depend on, for example, timetables. A lack of time presently appears to be a major constraint for physical activity behaviours (cf. Trost, Owen, Bauman et al., 2002). Therefore, active transport might have the potential to positively influence the desirable recommended daily level of physical activity, particularly active commuting to the place of work, since it is often done on a regular basis. Apart from the many advantages that active transport seems to constitute, there are some possible disadvantages. Active transport, especially bicycling, requires a physical effort, which sometimes can be tiresome. Active transports can, furthermore, be weather-dependent.

Compared to other means of transport, active transports are slow and disadvantageous for travelling longer distances and can be impractical for the transport of cumbersome loads. Although, active transports have some disadvantages, there are many advantages for both the individual and soci- ety. Active transport therefore constitutes an important research area.

2.2 Correlates of physical activity

A wide range of factors have been identified as correlates and potential determinants of adults’ participation in physical activity. Correlates refer to simple statistical associations and determinants refer to causal factors (Bauman, Sallis, Dzewaltowsk, 2002). Correlates of physical activity can be categorized as demographic and biological factors, psychological, cogni- tive, and emotional factors, behavioural attributes and skills, social and cultural factors, physical environment factors, and physical activity characteristics (for a review, see Trost et al., 2002). The theories and models used for research on correlates of physical activity have gone from specifying

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Figure 1. Physical activity specified by type and purpose.

The common view regarding the public recommendation for health- enhancing physical activity (HEPA) (Oja and Borms, 2004) is that people should accumulate at least 30 minutes of physical activity of at least moderate intensity on preferably all days of the week (Haskell, Lee, Pate et al., 2007; Pate, Pratt, Blair et al., 1995; Professional Associations for Physical Activity, Sweden 2003; 2008; U.S. Department of Health and Human Ser- vices, 1996; 2008). Moreover, a physically active lifestyle has been urged (Haskell et al., 2007). A physically active lifestyle or active living represents the incorporation of physical activity into normal and habitual daily living.

Thus, active transport – travelling by, e.g. foot or bicycle – could have an important potential for increasing people’s physical activity level (for a review, see Shephard, 2008) and thereby meeting the physical activity recommendation.

2.1.1 Active transport

Active transport or non-motorized travel, includes walking, bicycling, small-wheeled transports, such as inline skates and skateboards, and wheelchairs (Committee on Physical Activity, Health, Transportation and Land Use, 2005). The most common forms are walking and bicycling.

Active transport, i.e. walking and bicycling, has, however, generally de- clined in the industrialized world over the last decades (cf. Pucher and Buehler, 2010). Active transport and active commuting to the place of work have, from a theoretical point of view, the potential to influence public health positively – especially bicycle commuting, since it seems easier to meet the requested intensity level by bicycle compared to by foot (cf.

Shephard, 2008). Bicycle commuting could probably result in approxi- mately the same improvement in physical performance as specific training programmes (Hendriksen, Zuiderveld, Kemper et al., 2000). An associa-

Physical

activity Type

Walking Bicycling Other

- e.g. swimming, skating

Purpose Recreation Exercise Competition Transport Other

- e.g. household activities, occupa- tional activities

Purpose (destination) WorkOther - e.g. shop, bank

tion between active commuting and reduced cardiovascular risk has been recognized (for a meta-analytic review, see Hamer and Chida, 2008). A Swedish study (Lindström, 2008) demonstrated that active commuting to the place of work had a negative association with overweight and obesity.

Furthermore, transport bicycling and bicycle commuting have resulted in reduced all-cause mortality (Andersen, Schnohr, Schroll et al., 2000; Mat- thews, Jurj, Shu et al., 2007). Although more evidence is needed, regular bicycling will most likely have an impact on health, which will probably affect public health positively (for a systematic review, see Oja, Titze, Bauman et al., 2011). In conclusion, it seems that active transport has the potential to influence health positively.

Besides the likely health benefits, active transports also have other advantages, as well as disadvantages. Active transport could contribute fa- vourably to sustainable development and reduce noise and congestion levels. Active transport is, furthermore, less expensive than other means of transport and is ‘trustworthy’ and represents ‘freedom’ since it does not depend on, for example, timetables. A lack of time presently appears to be a major constraint for physical activity behaviours (cf. Trost, Owen, Bauman et al., 2002). Therefore, active transport might have the potential to positively influence the desirable recommended daily level of physical activity, particularly active commuting to the place of work, since it is often done on a regular basis. Apart from the many advantages that active transport seems to constitute, there are some possible disadvantages. Active transport, especially bicycling, requires a physical effort, which sometimes can be tiresome. Active transports can, furthermore, be weather-dependent.

Compared to other means of transport, active transports are slow and disadvantageous for travelling longer distances and can be impractical for the transport of cumbersome loads. Although, active transports have some disadvantages, there are many advantages for both the individual and soci- ety. Active transport therefore constitutes an important research area.

2.2 Correlates of physical activity

A wide range of factors have been identified as correlates and potential determinants of adults’ participation in physical activity. Correlates refer to simple statistical associations and determinants refer to causal factors (Bauman, Sallis, Dzewaltowsk, 2002). Correlates of physical activity can be categorized as demographic and biological factors, psychological, cogni- tive, and emotional factors, behavioural attributes and skills, social and cultural factors, physical environment factors, and physical activity characteristics (for a review, see Trost et al., 2002). The theories and models used for research on correlates of physical activity have gone from specifying

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psychological and social aspects focusing on interventions targeting indi- viduals to a broader perspective (cf. U.S. Department of Health and Hu- man Services, 1996), including ecological models, which in the public health field focus on people’s interactions with their physical and sociocul- tural environments (cf. Sallis and Owen, 2002). Ecological models are well suited for studying correlates of physical activity behaviours.

2.2.1 Ecological models of physical activity

Ecological models of physical activity consist of a wide range of influences of behaviours at various levels. Intrapersonal, interpersonal or cultural, organizational, physical environmental and policy factors are included in these models. To a varying degree, all levels of factors can influence behaviours concurrently. A person is surrounded by different environments and the interactions between a person and the environment constitutes behaviours. Both objective aspects and people’s perceptions of environments are likely to influence behaviours. For example, objective aspects, such as the quality and quantity of bicycle paths, may influence the likelihood of bicycling. Furthermore, if people think that the traffic environment is unsafe, although it is in fact safe, their perceptions could result in a non-bicycling behaviour. ‘Behaviour settings’, which are places were physical activity can occur, should also be considered regarding both access and characteristics (cf. Sallis and Owen, 2002; Sallis, Cervero, Ascher et al., 2006). Ecological models constitute a promising approach and Sallis et al. (2006) stated that such models are ‘well suited for studying physical activity, because physical activity is done in specific places. Studying characteristics of places that facilitate or hinder physical activity, therefore, is a priority’ (p. 299).

Sallis and Owen (2002) suggested that ecological approaches to health behaviour change should be behaviour-specific. This aspect of specificity was further promoted by Giles-Corti, Timperio, Bull et al. (2005). Among other things, they concluded and suggested that ‘future research might consider: 1) studying specific behaviors; 2) the context within which the behavior is performed; [and] 3) using context-specific behavior measures’

(Giles-Corti et al. 2005, p. 180). Studying bicycle commuting to the place of work (Figure 1) and the route environments within which the bicycle commuting is performed constitute such specificity.

2.3 Measuring the relation between physical activity and the environment

2.3.1 The development of the research field

The research on the relation between physical activity and environments is a relatively new area of research. A number of research strategies have, however, evolved, with the aim of measuring the relationship. They all have their strengths and limitations. Studies have appeared from mainly three fields: (1) health, including public health, exercise and behavioural sciences; (2) city or urban planning, including travel behaviour, transport planning, urban design and geography; and (3) parks, recreation and leisure sciences (cf. Sallis, 2009). Most of the influential research on the general relation between physical activity and the environment is found within the first two fields.

First out was the research in the field of urban planning. Research on travel behaviours, i.e. walking and bicycling for transport, and land use, design of communities, and design of transport systems have been studied since at least the 1980s. The goal for the urban planning field was to en- hance the quality of life by, for example, reducing traffic congestion and improving air quality. Residential density, land-use design, and pedestrian- oriented design, often defined as walkability, were the focus (cf. Sallis, 2009). The urban planning field contributes to our knowledge of active transport, but the focus is on a more aggregated community level (Handy, Boarnet, Ewing et al., 2002), which gives a rather crude understanding, leaving much to be learnt on an important individual level.

The focus on environments related to physical activity in the field of health is on a more disaggregated and individual level. Only a few studies in the health field were conducted before the mid-1990s. The physical activity behaviours of interest for the health field were recreational and leisure time physical activities. Social environments, access to recreational facilities, home equipment and neighbourhood attributes were studied (cf.

Sallis, 2009). The interest in the field of health for the relationship between active transport and the environment seems to originate mainly from the shift of focus regarding: (a) physical activity recommendations, moving from vigorous to moderate physical activity, emphasizing walking; and (b) behavioural change intentions, moving from interventions targeting indi- viduals to a broader perspective, including ecological models which em- phasize the importance of environments. Consequently, the health and physical activity research was influenced by the urban planning and transport research. One example is that by Saelens, Sallis and Frank (2003a) that prompted transport walkability characteristics (i.e. higher density,

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psychological and social aspects focusing on interventions targeting indi- viduals to a broader perspective (cf. U.S. Department of Health and Hu- man Services, 1996), including ecological models, which in the public health field focus on people’s interactions with their physical and sociocul- tural environments (cf. Sallis and Owen, 2002). Ecological models are well suited for studying correlates of physical activity behaviours.

2.2.1 Ecological models of physical activity

Ecological models of physical activity consist of a wide range of influences of behaviours at various levels. Intrapersonal, interpersonal or cultural, organizational, physical environmental and policy factors are included in these models. To a varying degree, all levels of factors can influence behaviours concurrently. A person is surrounded by different environments and the interactions between a person and the environment constitutes behaviours. Both objective aspects and people’s perceptions of environments are likely to influence behaviours. For example, objective aspects, such as the quality and quantity of bicycle paths, may influence the likelihood of bicycling. Furthermore, if people think that the traffic environment is unsafe, although it is in fact safe, their perceptions could result in a non-bicycling behaviour. ‘Behaviour settings’, which are places were physical activity can occur, should also be considered regarding both access and characteristics (cf. Sallis and Owen, 2002; Sallis, Cervero, Ascher et al., 2006). Ecological models constitute a promising approach and Sallis et al. (2006) stated that such models are ‘well suited for studying physical activity, because physical activity is done in specific places. Studying characteristics of places that facilitate or hinder physical activity, therefore, is a priority’ (p. 299).

Sallis and Owen (2002) suggested that ecological approaches to health behaviour change should be behaviour-specific. This aspect of specificity was further promoted by Giles-Corti, Timperio, Bull et al. (2005). Among other things, they concluded and suggested that ‘future research might consider: 1) studying specific behaviors; 2) the context within which the behavior is performed; [and] 3) using context-specific behavior measures’

(Giles-Corti et al. 2005, p. 180). Studying bicycle commuting to the place of work (Figure 1) and the route environments within which the bicycle commuting is performed constitute such specificity.

2.3 Measuring the relation between physical activity and the environment

2.3.1 The development of the research field

The research on the relation between physical activity and environments is a relatively new area of research. A number of research strategies have, however, evolved, with the aim of measuring the relationship. They all have their strengths and limitations. Studies have appeared from mainly three fields: (1) health, including public health, exercise and behavioural sciences; (2) city or urban planning, including travel behaviour, transport planning, urban design and geography; and (3) parks, recreation and leisure sciences (cf. Sallis, 2009). Most of the influential research on the general relation between physical activity and the environment is found within the first two fields.

First out was the research in the field of urban planning. Research on travel behaviours, i.e. walking and bicycling for transport, and land use, design of communities, and design of transport systems have been studied since at least the 1980s. The goal for the urban planning field was to en- hance the quality of life by, for example, reducing traffic congestion and improving air quality. Residential density, land-use design, and pedestrian- oriented design, often defined as walkability, were the focus (cf. Sallis, 2009). The urban planning field contributes to our knowledge of active transport, but the focus is on a more aggregated community level (Handy, Boarnet, Ewing et al., 2002), which gives a rather crude understanding, leaving much to be learnt on an important individual level.

The focus on environments related to physical activity in the field of health is on a more disaggregated and individual level. Only a few studies in the health field were conducted before the mid-1990s. The physical activity behaviours of interest for the health field were recreational and leisure time physical activities. Social environments, access to recreational facilities, home equipment and neighbourhood attributes were studied (cf.

Sallis, 2009). The interest in the field of health for the relationship between active transport and the environment seems to originate mainly from the shift of focus regarding: (a) physical activity recommendations, moving from vigorous to moderate physical activity, emphasizing walking; and (b) behavioural change intentions, moving from interventions targeting indi- viduals to a broader perspective, including ecological models which em- phasize the importance of environments. Consequently, the health and physical activity research was influenced by the urban planning and transport research. One example is that by Saelens, Sallis and Frank (2003a) that prompted transport walkability characteristics (i.e. higher density,

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greater connectivity, and more land-use mix) as being important for physical activity and health research. They also suggested that other factors, such as safety, pavements and bike lanes, and aesthetics and topography, possibly associated with active transport needed to be studied. On the basis of these recommendations, a self-report questionnaire, called the Neighborhood Environment Walkability Scales (NEWS), was developed in the U.S. (Saelens, Sallis, Black et al., 2003b). As the name implies, the focus of the scale is on assessing the neighbourhood environments related to walking.

Another example, partly inspired by urban planning and transport research, is a conceptual framework of environmental factors that may influence walking and bicycling in local neighbourhoods developed by Pikora, Giles-Corti, Bull et al. (2003). Four separate frameworks were developed:

one for recreational walking, one for transport walking, one for recreational bicycling and one for transport bicycling. There were differences between all four frameworks regarding the inclusion and magnitude of influences of environmental factors, emphasizing the importance of studying physical activity behaviours specifically. On the basis of this framework, an audit tool, called the Systematic Pedestrian and Cycling Envi- ronmental Scan (SPACES), was developed in Australia (Pikora, Bull, Jam- rozik et al., 2002).

The majority of the studies on physical environments have been conducted in the U.S. and Australia (cf. Wendel-Vos, Droomers, Kremers et al., 2007). In 2002, however, an international collaboration (the Interna- tional Prevalence Study (IPS)) was initiated with the aim of collecting national data from different countries for international comparisons. In addi- tion to the assessment of physical activity, an environmental module was developed to assess the local neighbourhood, complementing the Interna- tional Physical Activity Questionnaire (IPAQ) (cf. Alexander, Bergman, Hagströmer et al., 2006). Although it contributes to furthering our knowledge of environments related to physical activity, the focus on the local neighbourhood, also exemplified by the NEWS and the SPACES, it ex- cludes important aspects of the extended route environment related to active transport. This is one reason for the development of questionnaires that focus on the route environment (de Geus, De Bourdeaudhuji, Jannes et al., 2008; Titze, Stronegger, Janschitz et al., 2007).

In conclusion, the health and physical activity researchers have developed research strategies influenced by the urban planning work, which emphasized walkability. In contrast to the field of urban planning, which mainly acts on an aggregated level, the health field integrated walkability in research strategies mostly on a disaggregated level. The general envi-

ronmental focus is on the local neighbourhood. The conceptual framework developed by Pikora et al. (2003) emphasized the importance of studying physical activity behaviours specifically, and the IPS emphasized the importance of studying the relation between physical activity and the environment from an international perspective (cf. Alexander et al., 2006). In ad- dition to the research approaches in the fields of urban planning and health, the concept of space syntax was developed in the field of architec- ture as a tool for studying peoples’ movement in relation to buildings and cities (Space Syntax, viewed 23 November 2010,

<http://www.spacesyntax.org>). Other, additional research approaches include studying people’s route choices. This can be done by stated prefer- ence measures (e.g. Stinson and Bhat, 2003) or by comparing the shortest route with the actual route (Winters, Teschke, Grant et al., 2010a). All of these research strategies have their strengths and limitations. One limita- tion is that the vast majority of the studies are of cross-sectional design (cf.

Wendel-Vos et al., 2007) and therefore no causal relations can be estab- lished. Furthermore, self-selection, i.e. people’s choices and decisions to live in a specific area depending on their preferences, can influence the findings.

As mentioned, this research work is in a relatively early stage, exploring a complex field of research. Therefore, new research approaches are needed to further the state of knowledge about the relation between physical activity and the environment.

2.3.1.1 Walkability

In relation to bicycling, walking is a rather well studied behaviour in research on the relation between physical activity and the environment. One possible explanation is that most studies are conducted in the U.S. and Australia (cf. Wendel-Vos et al., 2007) where walking is more common than bicycling (cf. Pucher and Buehler, 2010). Regarding walking envi- ronments, walkability is a concept currently in focus. Regarding the eco- logical approach, Sallis et al. (2006) refer to walkability as a characteristic of a behavioural setting in relation to active transport and describe walkability of neighbourhoods as ‘the ability to walk to nearby destinations such as shops’ (p. 302). As mentioned, walkability originates from research in the field of urban planning on travel behaviours and land use and design (cf. Sallis, 2009). Walkability is frequently referred to as being dependent on levels of density, connectivity, land-use mix and pedestrian-oriented infrastructure. Handy et al. (2002, p. 66) have defined and explained the

‘walkability factors’ as the following: density is defined as the ‘amount of activity in a given area’ or ‘population, employment, or building square footage per unit of area’ and measured, for example, as ‘ratio of commer-

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