The Fundamental Law of Road Congestion: Evidence from US cities
We investigate the relationship between interstate highways and highway vehicle kilometers traveled (VKT) in US cities. We find that VKT increases proportionately to highways and identify three important sources for this extra VKT: an increase in driving by current residents; an increase in transportation intensive production activity; and an inflow of new residents. The provision of public transportation has no impact on VKT. We also estimate the aggregate city level demand for VKT and find it to be very elastic. We conclude that an increased provision of roads or public transit is unlikely to relieve congestion.
We thank Richard Arnott, Jan Brueckner, Victor Couture, Edward Glaeser, Penny Goldberg, Steve Kohlhagen, Andreas Kopp, David Levinson, Guy Michaels, Se-Il Mun, Ken Small, two anonymous referees, and seminar and conference participants for comments and suggestions, Byron Moldofsky for assistance with GIS and data processing, and Magda Biesiada for excellent research assistance. Financial support from the Canadian Social Science and Humanities Research Council and the Paris School of Economics is gratefully acknowledged by both authors. The views expressed herein are those of the author(s) and do not necessarily reflect the views of the National Bureau of Economic Research.
Gilles Duranton & Matthew A. Turner, 2011. "The Fundamental Law of Road Congestion: Evidence from US Cities," American Economic Review, American Economic Association, vol. 101(6), pages 2616-52, October. citation courtesy of