This study, conducted by researchers from PIRE’s Santa Cruz office (Sue Thomas, Ryan Treffers, Carol Cannon, and Lauren Heumann) was among the first cohort of studies funded by the Robert Wood Johnson Foundation’s Public Health Law Research program.

Zoning policies that segregate work, home, commercial, and public and civic daily use activities perpetuate automobile use as the primary mode of transportation and discourage daily physical activities such as walking or biking.  Public health is compromised by diminished physical activity, leading to poor health indicators, including obesity, diabetes, and cancer. Mixed use zoning is designed to increase the number and types of daily use activities present in a neighborhood, and can provide the groundwork for greater walkability, defined as being pedestrian-friendly, pedestrian-accessible or pedestrian-oriented.

Using a unique combination of legal policy research, walkability data collection, and interviews with city planners, this study asked whether land use zoning could create the conditions for improved public health.  Original legal data were collected from 168 mixed use ordinances in 22 California cities.  Each ordinance was coded for 39 use measures in categories of residential, public and civic, commercial, and industrial, and each was scored for closeness to the American Planning Association’s model mixed use zone.  On the walkability side, a random sample of up to two geographical zones per MUZ type (265 zones in total) was coded for 43 daily use activity categories.  Fifteen city planners were also interviewed about the history and implementation of MUZs in their cities.

The results demonstrated that, controlling for population size, socio-economic status (SES), and the area of each zone in square kilometers, the relationship between the comprehensiveness (closeness to the American Planning Association’s model) and the presence of daily use activities in the mixed use zones was statistically significant.  Further, the more comprehensive and stringent the legal scores for specific use categories, the greater the presence of these uses in the MUZs. 

This study is among the first to demonstrate the relationship between local land use zoning decisions and walkability, and how comparative, cross-sectional research can complement case study and archival approaches to public health studies of city design and its effects.

View poster and handout here.