The American Lung Association has joined forces with the Local Government Commission and a variety of groups interested in transportation, land use, and air quality issues. These groups are working together to ensure that communities grow smartly instead of sprawling, with the least impact on the environment. Research has shown that compact, pedestrian and transit-friendly communities have a positive impact on air quality by improving travel alternatives. According to the 1990 nationwide Personal Transportation Survey, households living in city centers take 18 percent fewer trips, make on average 18 percent shorter trips, and travel 36 percent fewer miles. Smart Growth and Diesel Communities that offer viable transportation alternatives are part of the Smart Growth plan.
Buses are an important part of a community's transportation system.
However, transit agencies need to start phasing out the use of diesel and replace old buses with new ones that are powered by alternative fuels such as natural gas, fuel cells or electricity. Diesel exhaust is a serious public health risk and has been listed as a known human carcinogen since 1990. Diesel exhaust also exacerbates lung diseases such as asthma and emphysema.