Keep on moving: Optimized placement of moving walkways in airport terminals

Since its inception in 1955, when Delta Airlines pioneered the hub-and-spoke system at their Atlanta hub, airports have been engaged in fierce competition to ensure efficient and dependable transfers for passengers and airlines between connecting flights. In line with this overarching objective, we present a long-term layout design problem that focuses on optimizing the placement of moving walkways within the corridors of an airport terminal. Our primary goal is to facilitate faster transfers on these walkways, thereby improving gate connectivity. To achieve this, we propose the following budget-constrained optimization task: Maximize the weighted number of gate pairs that passengers can transfer between, without exceeding the specified minimum connecting time for each gate pair. We mathematically formulate the resulting optimization problem and provide a comprehensive analysis of its computational complexity. Additionally, we introduce suitable solution methods to tackle this challenging optimization task. Through a comprehensive computational study, using real-world terminal data, we evaluate the performance of our solution approaches. Our results demonstrate that optimized walkway layouts significantly contribute to reliable connecting processes during daily airport operations.