Monechi Bernardo, Servedio Vito D P, Loreto Vittorio
Sapienza University of Rome, Physics Dept., Piazzale Aldo Moro 2, 00185 Roma, Italy.
Institute for Complex Systems (ISC-CNR), Via dei Taurini 19, 00185 Roma, Italy; Sapienza University of Rome, Physics Dept., Piazzale Aldo Moro 2, 00185 Roma, Italy.
PLoS One. 2015 May 20;10(5):e0125546. doi: 10.1371/journal.pone.0125546. eCollection 2015.
Air Transportation represents a very interesting example of a complex techno-social system whose importance has considerably grown in time and whose management requires a careful understanding of the subtle interplay between technological infrastructure and human behavior. Despite the competition with other transportation systems, a growth of air traffic is still foreseen in Europe for the next years. The increase of traffic load could bring the current Air Traffic Network above its capacity limits so that safety standards and performances might not be guaranteed anymore. Lacking the possibility of a direct investigation of this scenario, we resort to computer simulations in order to quantify the disruptive potential of an increase in traffic load. To this end we model the Air Transportation system as a complex dynamical network of flights controlled by humans who have to solve potentially dangerous conflicts by redirecting aircraft trajectories. The model is driven and validated through historical data of flight schedules in a European national airspace. While correctly reproducing actual statistics of the Air Transportation system, e.g., the distribution of delays, the model allows for theoretical predictions. Upon an increase of the traffic load injected in the system, the model predicts a transition from a phase in which all conflicts can be successfully resolved, to a phase in which many conflicts cannot be resolved anymore. We highlight how the current flight density of the Air Transportation system is well below the transition, provided that controllers make use of a special re-routing procedure. While the congestion transition displays a universal scaling behavior, its threshold depends on the conflict solving strategy adopted. Finally, the generality of the modeling scheme introduced makes it a flexible general tool to simulate and control Air Transportation systems in realistic and synthetic scenarios.
航空运输是一个非常有趣的复杂技术社会系统的例子，其重要性随着时间的推移大幅增长，其管理需要仔细理解技术基础设施与人类行为之间的微妙相互作用。尽管与其他运输系统存在竞争，但预计未来几年欧洲的空中交通仍将增长。交通负荷的增加可能会使当前的空中交通网络超出其容量限制，从而可能无法再保证安全标准和性能。由于无法直接研究这种情况，我们借助计算机模拟来量化交通负荷增加的潜在破坏可能性。为此，我们将航空运输系统建模为一个由人类控制的复杂动态航班网络，人类必须通过重新规划飞机轨迹来解决潜在的危险冲突。该模型通过欧洲一个国家空域的航班时刻表历史数据进行驱动和验证。在正确再现航空运输系统的实际统计数据（例如延误分布）的同时，该模型还允许进行理论预测。当系统中注入的交通负荷增加时，该模型预测会从一个所有冲突都能成功解决的阶段过渡到一个许多冲突无法再解决的阶段。我们强调，只要管制员使用一种特殊的重新规划程序，航空运输系统当前的飞行密度就远低于过渡点。虽然拥堵过渡呈现出普遍的标度行为，但其阈值取决于所采用的冲突解决策略。最后，所引入的建模方案具有通用性，使其成为一个灵活的通用工具，可用于在现实和合成场景中模拟和控制航空运输系统。
