Experimental Economics

, Volume 17, Issue 3, pp 461–487 | Cite as

Traffic congestion: an experimental study of the Downs-Thomson paradox

  • Emmanuel Dechenaux
  • Shakun D. MagoEmail author
  • Laura Razzolini
Original Paper


This study considers a model of road congestion with average cost pricing. Subjects must choose between two routes—Road and Metro. The travel cost on the road is increasing in the number of commuters who choose this route, while the travel cost on the metro is decreasing in the number of its users. We examine how changes to the road capacity, the number of commuters, and the metro pricing scheme influence the commuters’ route-choice behavior. According to the Downs-Thomson paradox, improved road capacity increases travel times along both routes because it attracts more users to the road and away from the metro, thereby worsening both services. A change in route design generates two Nash equilibria; and the resulting coordination problem is amplified even further when the number of commuters is large. We find that, similar to other binary choice experiments with congestion effects, aggregate traffic flows are close to the equilibrium levels, but systematic individual differences persist over time.


Congestion Laboratory experiments Downs-Thomson Paradox Coordination 

JEL Classification

C91 C92 D83 R40 R41 

Supplementary material

10683_2013_9378_MOESM1_ESM.pdf (115 kb)
Instructions (PDF 115 kB)


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Copyright information

© Economic Science Association 2013

Authors and Affiliations

  • Emmanuel Dechenaux
    • 1
  • Shakun D. Mago
    • 2
    Email author
  • Laura Razzolini
    • 3
  1. 1.Kent State UniversityKentUSA
  2. 2.University of RichmondRichmondUSA
  3. 3.Virginia Commonwealth UniversityRichmondUSA

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