It may have taken a major oil spill in the Gulf of Mexico to direct the general public’s attention to automobile use and how it affects everything from the environment to obesity. But some people study it—and how to change that habit and its impacts on energy consumption, air quality, climate, physical activity and more—every day. A study featured in the summer issue of the Journal of the American Planning Association, and released in advance this week, aims to make decisions easier for those charged with designing and building cities that use less carbon in the future. “There has...