title: Association between neighborhood walkability and GPS-measured walking, bicycling and vehicle time in adolescents.
abstract: OBJECTIVE
  To investigate relations of walking, bicycling and vehicle time to neighborhood walkability and total physical activity in youth.
  
  
  METHODS
  Participants (N=690) were from 380 census block groups of high/low walkability and income in two US regions. Home neighborhood residential density, intersection density, retail density, entertainment density and walkability were derived using GIS. Minutes/day of walking, bicycling and vehicle time were derived from processing algorithms applied to GPS. Accelerometers estimated total daily moderate-to-vigorous physical activity (MVPA). Models were adjusted for nesting of days (N=2987) within participants within block groups.
  
  
  RESULTS
  Walking occurred on 33%, active travel on 43%, and vehicle time on 91% of the days observed. Intersection density and neighborhood walkability were positively related to walking and bicycling and negatively related to vehicle time. Residential density was positively related to walking.
  
  
  CONCLUSIONS
  Increasing walking in youth could be effective in increasing total physical activity. Built environment findings suggest potential for increasing walking in youth through improving neighborhood walkability.
authors.affiliation: Department of Family Medicine and Public Health, University of California, San Diego, 3900 Fifth Avenue, Suite 310, San Diego, CA 92103, USA. Electronic address: jacarlson@ucsd.edu.
authors.forename: Jordan A
authors.initials: JA
authors.lastname: Carlson
authors.affiliation: Department of Pediatrics, University of Washington & Children׳s Hospital and Regional Medical Center, 1100 Olive Way, Suite 500, Seattle, WA 98101, USA. Electronic address: bsaelens@u.washington.edu.
authors.forename: Brian E
authors.initials: BE
authors.lastname: Saelens
authors.affiliation: Department of Family Medicine and Public Health, University of California, San Diego, 9500 Gilman Drive ♯ 0811, La Jolla, CA 92093, USA. Electronic address: jkerr@ucsd.edu.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Kerr
authors.affiliation: University of Southern Denmark, Department of Sports Science and Clinical Biomechanics, Campusvej 55, 5230 Odense, Denmark. Electronic address: jschipperijn@health.sdu.dk.
authors.forename: Jasper
authors.initials: J
authors.lastname: Schipperijn
authors.affiliation: Department of Family Medicine and Public Health, University of California, San Diego, 3900 Fifth Avenue, Suite 310, San Diego, CA 92103, USA. Electronic address: tlconway@ucsd.edu.
authors.forename: Terry L
authors.initials: TL
authors.lastname: Conway
authors.affiliation: School of Community and Regional Planning, University of British Columbia, Vancouver BC, ♯433-6333 Memorial Road, Vancouver, BC V6T 1Z2, Canada. Electronic address: ldfrank@urbandesign4health.com.
authors.forename: Lawrence D
authors.initials: LD
authors.lastname: Frank
authors.affiliation: Urban Design 4 Health, 353 Rockingham St., Rochester, NY 14620, USA. Electronic address: jchapman@ud4h.com.
authors.forename: Jim E
authors.initials: JE
authors.lastname: Chapman
authors.affiliation: Perelman School of Medicine and School of Nursing, 801 Blockley Hall, 423 Guardian Drive, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address: kglanz@upenn.edu.
authors.forename: Karen
authors.initials: K
authors.lastname: Glanz
authors.affiliation: Department of Family Medicine and Public Health, University of California, San Diego, 3900 Fifth Avenue, Suite 310, San Diego, CA 92103, USA. Electronic address: kcain@ucsd.edu.
authors.forename: Kelli L
authors.initials: KL
authors.lastname: Cain
authors.affiliation: Department of Family Medicine and Public Health, University of California, San Diego, 3900 Fifth Avenue, Suite 310, San Diego, CA 92103, USA. Electronic address: jsallis@ucsd.edu.
authors.forename: James F
authors.initials: JF
authors.lastname: Sallis
mesh_terms: D061725:Accelerometry; D000293:Adolescent; D000294:Adolescent Behavior; D000465:Algorithms; D001336:Automobiles / Q000706:statistics & numerical data*; D015142:Baltimore; D001642:Bicycling / Q000706:statistics & numerical data*; D002648:Child; D015444:Exercise; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D008297:Male; D012111:Residence Characteristics; D014186:Transportation; D016138:Walking / Q000706:statistics & numerical data*; D014861:Washington
keywords: Density; Land use; Mode share; Physical activity; Transportation