Vertiport Siting Optimization for Urban Air Mobility (UAM) Services

The deployment of Urban Air Mobility (UAM) services has the potential to significantly reshape urban and regional transport systems by providing point-to-point fast connections. However, UAM services remain strongly dependent on ground-based infrastructure, namely vertiports, whose location critically affects service accessibility, demand levels, and economic viability. Existing studies often address vertiport siting from a single decision-making perspective, thereby overlooking the fact that different stakeholders (e.g., infrastructure managers and UAM operators) may adopt distinct optimality criteria when identifying the network configuration and its evolution over time. This study proposes a hybrid heuristic optimization framework for the joint determination of the number and spatial distribution of vertiports within a given study area. The framework integrates a multimodal demand model with a two-stage optimization procedure combining a genetic algorithm and an advanced greedy search. Two optimality criteria are modelled to reflect different decision-making preferences: the Vertiport Manager (VM), aiming to maximize infrastructure utilization through served demand, and the Transport Operator (TO), aiming to maximize revenues generated by distance-based passenger fares. The methodology is applied to the Lombardy Region (Italy), where a large-scale data collection campaign was conducted for the estimation of a multimodal mode choice model. Two main results emerge from the analysis.  First, although optimal mature vertiport network configurations tend to converge across the two decision-making logics, their development trajectories differ substantially in the early stages. TO-oriented strategies favor more spatially dispersed networks and longer connections, whereas VM-oriented strategies promote early densification in high-demand central corridors.  Second, the results show a rapid increase in UAM demand in the initial phases of network development, when only a limited number of vertiports are deployed. This growth is followed by a saturation phase, occurring around 9–12 vertiports, beyond which the addition of further sites generates marginal benefits that are insufficient, from a private perspective, to justify investment in new infrastructure. These findings reveal a potential tension between economic sustainability and stakeholders’ network development strategies, as financially viable network configurations may correspond to stages of network development in which differences between VM- and TO-oriented are most pronounced. This highlights the importance of coordinated planning of UAM deployment and demonstrates how pricing schemes and governance arrangements can act as key levers to steer network evolution.