Neighborhood design as a strategy for improving air quality: Evidence from Northern California

The sprawling patterns of land development common to metropolitan areas of the US have been blamed for high levels of automobile travel, and thus for air quality problems. In response, smart growth programs - designed to counter sprawl - have gained popularity in the US. Studies show that residents of neighborhoods with higher levels of density, land-use mix, transit accessibility, and pedestrian friendliness drive less than residents of neighborhoods with lower levels of these characteristics. However, these studies have shed little light on the underlying direction of causality - whether neighborhood design influences travel behavior or whether travel preferences influence the choice of neighborhood. The available evidence thus leaves a key question largely unanswered: if cities use land use policies to bring residents closer to destinations and provide viable alternatives to driving, will people change their behavior in ways that reduce emissions? This study examines evidence from a study of residents of eight neighborhoods in Northern California on the link between neighborhood design and two behaviors that affect emissions: driving and choice of vehicle type. The study used multivariate modeling techniques to control for socio-demographic characteristics as well as attitudes and preferences. The results support the premise that land use policies have at least some potential to reduce driving and ownership of light duty trucks, thereby reducing emissions. Copyright ASCE 2008.