The Wall Street Journal’s recent article called “The Hidden Toll of Traffic Jams” highlights some truly jaw-dropping studies about the health impacts of exposure to vehicle exhaust. We’ve heard about the cardiac and respiratory effects of air pollution before, but according to the article vehicle exhaust has also been linked to a variety of other issues such as premature birth, autism, and Alzheimer’s disease.
The scientists responsible for these studies are rightly committed to further validating the results and separating out confounding effects, for example one who is cited as saying that “air pollution might be a risk factor for autism.” However, I disagree with this scientist when she says that “it is too soon for alarm.” These studies should be sounding loud alarms for the planners and engineers responsible for managing the transportation system because health impact is currently very low on our list of planning and design considerations. For example, in a review I did last year of the performance measures used by 45 State DOTs, only two states were found to use health-related measures, three states used emissions-related measures, and seven states used measures related to congestion or delay.
Whatever the biological pathways may be, it is clear that traffic congestion is negatively affecting human health in a variety of ways. By all means the biologists should keep working to understand the particulars. In the meantime, though, transportation professionals should be taking note and making our own changes. A few heartening examples of how transportation improvements have been associated with improved health or air quality are noted in the Wall Street Journal’s article.