Southwest Airlines’ lack of a hub-and-spoke network makes it more resilient to a number of disruptions, from weather problems to terrorism. But it’s easy to make the other airlines’ hub-and-spoke networks more robust.
Using network simulations, SFI External Professor Raissa D’Souza and collaborators Daniel Wuellner and Soumen Roy, all of UC Davis, show that while hub-and-spoke networks are more economically efficient on good days, they are more susceptible to random interruptions (such as bad weather) and local interruptions (such as airport security shutdowns).
Flight networks with large, densely connected subnetworks called “k-cores” – like Southwest’s network – remain better connected when speci c ights or airports are removed. Southwest’s average travel time increased only 4 percent in the simulations after removing a targeted 10 percent of its airports, while travel times for the next-best airline, American, increased 25 percent.
Fortunately, the authors argue, it’s easy to make the whole network more robust by concentrating on small subnetworks and adding routes there.
Their paper was published November 2 in Physical Review E.