The Prisoners` Dilemma and City-Centre Traffic

Such problems as inner-city traffic congestion and pollution are often asserted to be examples of the n-person Prisoners` Dilemma Game (PD), but there is a dearth of empirical research that tests this assertion. 551 car owners in Oxford responded to three pairs of alternatives designed as traffic versions of the four outcomes of the PD, by stating which alternative in each pair they preferred. Only 2% of respondents showed the full set of preferences which fit the PD. Four sets of preferences were common and accounted for 93% of responses suggesting that no single canonical game structure represents the traffic problem. The most common set of preferences, shown by 48% of respondents, fitted an `Assurance Game`. The results imply that the current city-centre traffic problem may be in substantial part due to lack of assurance and trust rather than raw self-interest. The public policy implications of the results are discussed