Citation

McFadden D. Transp. Policy 2007; 14(4): 269-274.

Copyright

(Copyright © 2007, Elsevier Publishing)

DOI

10.1016/j.tranpol.2007.07.001

PMID

unavailable

Abstract

One can think of transportation as a technological behemoth bedeviled by human behavior. Transportation research contributes technological and management innovations that drive this beast forward, and can also offer insights into the limits that human actors and institutions can impose on implementation of an efficient transportation system. Transportation is affected by human behavior through its consumers (drivers, riders, vehicle buyers, and shippers); through its managers and workers; and through the policy-makers and voters who determine transportation infrastructure and policy. In this presentation, I will concentrate on consumers, and add some comments on their influence on policy. However, human behavior impinges on transportation systems at many points. When I was 8 years old, a neighbor was promoted to conductor on the Southern Railroad. I asked him if he would be working on the Southern Crescent, the premier passenger train on that railroad. "Oh no," he said, "if I did that, I would have to deal with people. Railroad men would rather work with freight." Today, it is important for transportation workers, and transportation researchers, to recognize that there is no escape from humans and the impact of their behavior on transportation systems. One has to work with people.

Transportation researchers have modeled consumer behavior at three levels. First, physical analogies have been used, such as explaining trip volumes by the gravity model for attraction between bodies, or traffic with hydrodynamic models of fluid and turbulent flow. Second, there is extensive use of the economic theory of rational behavior, in which individuals make choices to maximize their preferences. Finally, there is increasing use of models of behavior that is not exactly individually rational, drawing on findings from sociology, anthropology, cognitive psychology, and brain science. A question for transportation researchers is what level of modeling of behavior is appropriate for their problems. One answer is that it depends on the grain of the problem. Physical analogies may be adequate for aggregate, long-term forecasting, economic optimizing models may be most satisfactory for dealing with issues such as congestion charges and fuel efficiency standards, and the insights of cognitive psychology may be needed to understand driving behavior. A second answer is that economic and behavioral sciences are progressing rapidly, and what works best in transportation research may change as time goes on.

I will start with three historical examples of the role of economic models of behavior in transportation. They are the linking of demand and utility by the French bridge engineer, Dupuit (1844); the application by Ravenstein (1885) and Zipf (1946) of Newton's law of gravitation to explain peoples' movements; and the development by Domencich and McFadden (1976) of disaggregate travel demand forecasting models based on random utility maximization.