Reducing automobile traffic: an urgent policy for health promotion.

In recent decades traffic injuries have become a leading cause of death and disability the world over. In congested urban areas, the noise and emissions from vehicle engines cause discomfort and disease. More than one billion people are exposed daily to harmful levels of atmospheric contamination. Because internal combustion generates carbon dioxide (CO2), the automobile is a principal contributor to the greenhouse effect, which has significantly raised the temperature of the atmosphere. Scientists anticipate that in coming decades the greenhouse effect will produce alterations in climate that are very likely to be harmful and possibly catastrophic. Meanwhile, burgeoning traffic and rural and urban highway infrastructures are already among the principal causes of environmental degradation. Urban development, because it is nearly always "planned" to accommodate automobiles rather than people, reduces the quality of life and tears the social fabric. In contrast to private automobiles, public transportation, bicycles, and walking produce little environmental contamination or injury-related morbidity and mortality. These modes of transport involve more physical activity, with its positive health effects, and avoid contributing to the greenhouse effect. The reduction of automobile traffic and substitution of alternative modes of transport are essential policies for health promotion. They should be incorporated in "healthy cities" programs and general economic policies.