Positive Feedback Model of Multiple-Airport Systems

A model for allocating passenger traffic in a multiple-airport system is proposed and tested. The model treats the supply side of the system as endogenous, and represents it implicitly using the principle that as traffic using an airport increases, the airport becomes more attractive. This positive feedback effect and the preference of air travelers for airports near their trip terminus are argued to be the key factors determining the distribution of traffic in a multiple-airport system. The model is applied to the San Francisco Bay Area, served by airports in Oakland, San Francisco, and San Jose. A disaggregate logit airport-choice model, in which airport utility is a function of travel time to trip origin, airport traffic in the origin-and-destination market, and airport enplanements, is estimated. The calibrated choice model, combined with estimates of the distribution of trip origins, is used to calculate equilibrium market shares. Comparison of equilibria with observed shares shows high correlation, particularly for larger markets, and for the San Francisco and Oakland airports.