title: International comparisons of the associations between objective measures of the built environment and transport-related walking and cycling: IPEN Adult Study.
abstract: BACKGROUND
  Mounting evidence documents the importance of urban form for active travel, but international studies could strengthen the evidence. The aim of the study was to document the strength, shape, and generalizability of relations of objectively measured built environment variables with transport-related walking and cycling.
  
  
  METHODS
  This cross-sectional study maximized variation of environments and demographics by including multiple countries and by selecting adult participants living in neighborhoods based on higher and lower classifications of objectively measured walkability and socioeconomic status. Analyses were conducted on 12,181 adults aged 18-66 years, drawn from 14 cities across 10 countries worldwide. Frequency of transport-related walking and cycling over the last seven days was assessed by questionnaire and four objectively measured built environment variables were calculated. Associations of built environment variables with transport-related walking and cycling variables were estimated using generalized additive mixed models, and were tested for curvilinearity and study site moderation.
  
  
  RESULTS
  We found positive associations of walking for transport with all the environmental attributes, but also found that the relationships was only linear for land use mix, but not for residential density, intersection density, and the number of parks. Our findings suggest that there may be optimum values in these attributes, beyond which higher densities or number of parks could have minor or even negative impact. Cycling for transport was associated linearly with residential density, intersection density (only for any cycling), and land use mix, but not with the number of parks.
  
  
  CONCLUSIONS
  Across 14 diverse cities and countries, living in more densely populated areas, having a well-connected street network, more diverse land uses, and having more parks were positively associated with transport-related walking and/or cycling. Except for land-use-mix, all built environment variables had curvilinear relationships with walking, with a plateau in the relationship at higher levels of the scales.
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark.
authors.forename: Lars B
authors.initials: LB
authors.lastname: Christiansen
authors.affiliation: School of Public Health, The University of Hong Kong, Hong Kong, China; Centre of Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Australia.
authors.forename: Ester
authors.initials: E
authors.lastname: Cerin
authors.affiliation: McCaughey VicHealth Community Wellbeing Unit, The University of Melbourne, Australia.
authors.forename: Hannah
authors.initials: H
authors.lastname: Badland
authors.affiliation: Center for Wireless & Population Health Systems, Department of Family Medicine & Public Health, University of California San Diego, USA.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Kerr
authors.affiliation: Centre for Research & Action in Public Health, Health Research Institute, University Canberra, Australia.
authors.forename: Rachel
authors.initials: R
authors.lastname: Davey
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Troelsen
authors.affiliation: Department of Movement and Sports Sciences, Ghent University, Belgium.
authors.forename: Delfien
authors.initials: D
authors.lastname: van Dyck
authors.affiliation: Institute of Active Lifestyle, Palacký University, Czech Republic.
authors.forename: Josef
authors.initials: J
authors.lastname: Mitáš
authors.affiliation: The Human Potential Centre, Auckland University of Technology, New Zealand.
authors.forename: Grant
authors.initials: G
authors.lastname: Schofield
authors.affiliation: Centre for Design Innovation, Swinburne University of Technology, Australia.
authors.forename: Takemi
authors.initials: T
authors.lastname: Sugiyama
authors.affiliation: Michael & Susan Dell Center for Healthy Living, The University of Texas Health Science Center at Houston, School of Public Health (Austin Regional Campus), USA; Center for Nutrition and Health Research, National Institute of Public Health, Mexico.
authors.forename: Deborah
authors.initials: D
authors.lastname: Salvo
authors.affiliation: Department of Public Health School of Medicine Universidad de los Andes, Bogota Colombia.
authors.forename: Olga L
authors.initials: OL
authors.lastname: Sarmiento
authors.affiliation: Pontiff Catholic University of Parana, Brasil; Federal University of Parana, Brasil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Reis
authors.affiliation: School of Nutrition and Health Promotion, Arizona State University, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Adams
authors.affiliation: School of Community and Regional Planning and the School of Population and Public Health, The University of British Columbia, Vancouver, Canada.
authors.forename: Larry
authors.initials: L
authors.lastname: Frank
authors.affiliation: Department of Family Medicine and Public Health, University of California San Diego, USA.
authors.forename: James F
authors.initials: JF
authors.lastname: Sallis
keywords: IPEN; built environment; cycling; international; transport; walking