title: Spatial and temporal patterns of North Carolina pedestrian and bicycle plans.
abstract: BACKGROUND
  Pedestrian and bicycle plans support community-level physical activity. In North Carolina, pedestrian/bicycle plans are becoming more prevalent. However, no studies have examined the spatial and temporal diffusion of pedestrian/bicycle plans.
  
  
  OBJECTIVE
  This study assessed (a) temporal trends associated with municipal pedestrian/bicycle planning from 1974 to 2011 and (b) spatial patterns associated with municipal plans, specifically, whether the publication of a pedestrian/bicycle plan in a given year was associated with the number of neighboring municipalities with plans.
  
  
  METHODS
  North Carolina from 1974 to 2011.
  
  
  METHODS
  The main outcome was date of publication of all North Carolina municipal pedestrian and bicycle plans (1974-2011). We calculated Euclidean distances from each municipality center to all other municipality centers to derive whether municipalities were within 20 and 50 miles of each other. Sociodemographic covariates (eg, education, grant funding status, poverty, urbanicity, racial composition, population size, population growth) were collected from the US Census of Population (1980-2010) and the American Community Survey (2006-2010). Time series models fitted by generalized estimating equations were used to assess relationships between plan presence and the temporal and spatial predictor variables.
  
  
  RESULTS
  The number of pedestrian and bicycle plans significantly increased over time, especially after 2006 when a state grant funding program was initiated. Unadjusted models indicated that municipalities were significantly more likely to have a pedestrian plan if higher numbers of neighboring municipalities had pedestrian plans. After adjustment for sociodemographic covariates and funding source, this relationship was attenuated but remained statistically significant. For bicycle plans, no significant associations were observed between plan presence and the number of neighboring municipalities with bicycle plans in adjusted models.
  
  
  CONCLUSIONS
  Findings from this study can be used to generate hypotheses to test theories about diffusion of innovation and social contagion processes in pedestrian/bicycle planning.
authors.affiliation: Department of Health Management and Policy, University of New Hampshire, Durham, New Hampshire 03824, USA. s_aytur@yahoo.com
authors.forename: Semra A
authors.initials: SA
authors.lastname: Aytur
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Rodriguez
authors.forename: Zachary Y
authors.initials: ZY
authors.lastname: Kerr
authors.forename: Kai
authors.initials: K
authors.lastname: Ji
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Evenson
mesh_terms: D001642:Bicycling; D002947:Cities; D002958:City Planning / Q000379:methods / Q000458:organization & administration*; D004779:Environment Design; D006801:Humans; D009111:Local Government; D009657:North Carolina; D016138:Walking