Health and Transportation Project

Americans are increasingly encouraged to use public transportation (PT) rather than cars to commute to work in order to reduce traffic congestion, usage of fossil fuels, and air pollution. In 2007, Americans took 10.3 billion PT trips, a 32% increase compared to 1995, and a faster growth than that of highway trips, or of the US population. Approximately 59% of transit use involves traveling to and from work. Use of PT will most likely be stimulated by financial reasons, growing consciousness of the environmental cost of car transportation, and better infrastructure. 

Public transportation commuting involves moderate walking, standing, and stair climbing. Commute time provides an ideal opportunity to add moderate activity to everyday life. Commuting is so prevalent and so central to the daily life of most people that it could very well become a major tool in the attempt to reverse the trends towards an increasingly sedentary lifestyle in the United States. 

Our mission is to document the potential beneficial effects and also rule out possible deleterious aspects of PT before it is integrated into a mass prevention strategy against obesity and major non-communicable causes of death such as cancer and cardiovascular diseases. Our research has documented and quantified the amount of extra physical activity PT commuters do compared to car commuters. We have shown that, in New York City, the exposure to air pollution of PT commuters is not substantially different from that of car commuters. 

We have also shown that when car drivers switched to ride PT for their work commute, they spent an extra 100 kilocalories per day which may prove to be crucial for limiting weight gain over time.

Contact: Professor Alfredo Morabia 

Alfredo Morabia
Alfredo Morabia

Alfredo Morabia has an MD from the University of Geneva, and a PhD in Epidemiology and an MS in Biostatistics, from The Johns Hopkins University. He was Professor and Head of the Division of Clinical Epidemiology at the Geneva University Hospital from 1990 to 2005, and has, since 2006, held the position of Professor of Epidemiology at the Center for the Biology of Natural Systems at Queens College, CUNY, and at the Department of Epidemiology of Columbia University, New York. His current research interests include the assessment of the impact of public transportation on commuter's health, and the description and analysis of when, why and how epidemiologic methods and concepts appeared and evolved. He is Chief Editor of Preventive Medicine, and Editor of the James Lind Library ( and of the People's Epidemiology Library (