Being fair or efficient? A fairness-driven modeling extension to the strategic airport slot scheduling problem

Abstract

An increasing thrust of research has recently explored scheduling methods and models with a view to allocating efficiently scarce airport slots among competing airlines, a problem also known as strategic airport slot scheduling. Existing models have mainly placed the research focus on scheduling efficiency objectives, while it was only recently that fairness considerations were introduced in relevant literature. Borrowing principles from congestion pricing, our paper capitalizes on the conjecture that the intensity of congestion and delay phenomena are strongly affected not only by the demand volumes but also the temporal distribution and peaking characteristics of demand. Hence, we propose a fairness-informed extension of the strategic airport slot scheduling model aiming to ensure that each airline absorbs its "fair share" of congestion in the form of additional schedule displacement exerted onto other competing users. The results of the proposed model are demonstrated and validated in two IATA schedule coordinated airports in Portugal and Greece. The newly proposed fairness weights penalize mostly the "big contributors to congestion", assigning them with higher displacement weights on the basis of "the contributor pays" principle. Furthermore, we assess the "cost of fairness" by quantifying the impacts of fairness-driven scheduling on efficiency and various Level of Service indicators. The main findings of our research suggest that the adoption of the proposed fairness-driven scheduling approach may come at reasonable "cost" particularly at low or moderate fairness levels as compared to the previous "fairness indifferent" case.