Background
Zoning code reforms have emerged throughout the U.S. as a potential policy strategy for reducing sprawl, reliance on cars, and increasing physical activity (PA) opportunities.(1-3) Code reforms seek to create pedestrian-friendly neighborhoods with increased street connectivity, mixed-use and higher density, open space, transportation infrastructure, and a traditional neighborhood structure. (1-3) Zoning code reforms have been adopted by jurisdictions in at least 35 states, with the number of communities considering such reforms increasing regularly.(4-6) The purpose of this study was to examine the relationship between zoning code reforms/zoning codes containing more active living-oriented requirements (e.g., trails, connectivity, parks, open space, etc.) and adult PA.

Objectives
To examine the relationship between the proportion of county populations exposed to zoning code reforms and/or active living-oriented zoning provisions and adult PA behaviors (i.e., biking, vigorous biking, walking, running/jogging, and vigorous running/jogging).

Methods
Zoning codes effective as of 2010 for the 97 most populous counties in the U.S. (covering 40% of the U.S. population) and 1,261 municipal jurisdictions located in those counties were compiled (representing 98% of all municipal jurisdictions in the 97 counties with populations >=0.5% of a given county's population). Zoning codes were coded by trained Master’s level urban planners using a systematic zoning code audit tool developed by the study team. Code reform zoning (=1) if a given jurisdiction’s zoning code was a new urbanist type of code (e.g., SmartCode) or the zoning code was form-based or included transects, pedestrian-oriented developments, transit-oriented developments, or traditional neighborhood developments. Other active living-oriented provisions coded included requirements for: sidewalks, crosswalks, bike-pedestrian connectivity, street connectivity, bike lanes, bike parking, bike-pedestrian trails/paths, mixed use development, active recreation (e.g., playgrounds, recreation structures, play areas, golf courses, parks with trails/amenities, exercise areas, etc.); and passive recreation (e.g., open space, greenways, nature preserves, generic parks). The zoning provisions for each jurisdiction were multiplied by the proportion of the county population represented by the given population and summed to a county-level, population-weighted measure of population exposure to a code reform zoning or active living-oriented zoning provisions. Zoning measure are continuous and range from 0-1 with 1 representing that the entire county population was exposed to a given measure and 0 indicating no exposure. Individual-level adult PA behaviors were obtained from the 2011 Behavioral Risk Factor Surveillance System (BRFSS), which  included 59,786 adults residing in the 97 counties of interest. Zoning data were lagged onto BRFSS data for analyses and were linked using state and county geocodes. Multivariate logistic regression models, controlling for individual demographics and BMI and county-level factors (deprivation index, race/ethnicity, Southern region) were computed to predict the odds of adult biking, vigorous biking, walking, running/jogging, and vigorous running/jogging.

Results
Descriptive statistics for the sample are presented in Table 1 and the full logistic regression results are presented in Table 2. In summary, the multivariate results indicate that for a 1-percentage point increase in the proportion of the population exposed to code reform zoning or zoning requirements for sidewalks, bike lanes, bike parking, bike-pedestrian trails/paths, active recreation, and/or passive recreation, the odds of adult biking and walking are statistically higher when controlling for individual and county-level factors. For example, for a 1-percentage point increase in the mean population exposure to zoning requirements for bike-pedestrian trails/paths, the odds of biking increases by 74%. Similarly, for a 1-percentage point increase in the mean population exposure to zoning requirements for sidewalks, the odds of adult walking increases by 13%.  Bike-pedestrian connectivity is associated with higher odds (OR=1.30, 95% CI: 1.02-1.65) of adult biking but no other PA measure. And, adult running/jogging was only associated with zoning requirements for bike lanes, mixed use, and active recreation. Overall, the most common zoning provisions to be associated with increased adult PA were code reform zoning and requirements for sidewalks, bike lanes, bike parking, active recreation, and passive recreation and, to a lesser extent, requirements for bike-pedestrian connectivity, bike-pedestrian trails/paths, and mixed use.

Conclusions
Zoning code reforms and more active living-oriented zoning provisions are associated with increased odds of adult PA.

Implications
Jurisdictions nationwide are seeking to identify policy and environmental strategies for increasing adult PA. Implementing changes to zoning codes to be more active living-oriented may be a key strategy for improving adult population-level PA in communities.

References

1. Schilling J, Linton LS. The public health roots of zoning: In search of active living's legal genealogy. Am J Prev Med. 2005;28:96-104.
2. Schilling J, Mishkovsky N. Creating a Regulatory Blueprint for Healthy Community Design: A Local Government Guide to Reforming Zoning and Land Development Codes. E-43346. 2005. Washington, D.C., ICMA.
3. American Planning Association. Planning and Urban Design Standards. 1st ed. Hoboken, NJ: John Wiley & Sons, Inc., 2006.
4. SmartCodes adopted collaborative map. Updated 2013. Accessed April 11, 2014.
5. SmartCodes in progress collaborative map. Updated 2013. Accessed April 11, 2014.
6. Other form-based codes collaborative map. Updated 2013. Accessed April 11, 2014.

Support / Funding Source
R01CA158035, National Cancer Institute, National Institutes of Health--Impact of Zoning Code Reforms on the Built Environment, Attitudes, and Physical Activity Behaviors (PI: Chriqui).