Evidence of the health impacts of the built environment has increased rapidly. Studies have linked physical inactivity and motor-vehicle pollution to a range of health problems and have shown that activity levels and air quality are influenced by community design, land use, and transportation patterns. There iscomparatively little awareness, however, of the role that laws and policies play in spurring sprawl and driving and of the opportunities to reorient current provisions to promote public health. This article summarizes the findings connecting the built environment to a variety of health problems. It then describes how current policies present barriers to physical activity and increase pollution by encouraging sprawl development and by offering few transportation choices. Finally, the article suggests ways to overcome these barriers by examining policies that can promote public health by making it easier to incorporate greater physical activity into our everyday lives and to reduce driving. Multidisciplinary partnerships are needed to pursue these policy prescriptions for healthier communities.