Air Route Networks Research Articles

Enhancing air traffic operational efficiency by reducing network scale

The growing demand for air travel has led to the saturation of air traffic networks. Conventional methods of adding routes to alleviate congestion and reduce delays may not achieve the desired effect and even degrade system performance. In this paper, we explore the application of Braess’s Paradox in the reduction of air traffic networks. This counterintuitive phenomenon shows that adding new connections to a network can actually increase the overall network pressure. This study uses Hidden Markov methods and the Viterbi algorithm to match air traffic flow with routes, a machine learning approach and a mathematical method to construct cost functions for flight time and traffic volume, and finally uses genetic algorithm and the A* algorithm to detect Braess’s Paradox edges. We uses ADS-B data from the busy month of July 2019 for a case study of the air traffic network over the UK airspace. The results show that Braess’s Paradox is also applicable to multi-flight level air route networks. Removing such network edges can improve system performance. In one day’s case, the total flight time of the day’s traffic volume decreased from 11509.24 minutes to 10459.97 minutes. This equates to an average savings of 4.99 minutes of flight time per flight, which is significant in controlling delay performance.

Research on eVTOL Air Route Network Planning Based on Improved A* Algorithm

With the continuous opening of low-altitude airspace and the development of aircraft such as electric vertical takeoff and landing (eVTOL) vehicles, urban air traffic has become a sustainable and green development direction for future transportation. Air route networks, as a mainstream design scheme for air traffic, are able to provide prerequisites for eVTOL and other green aircraft to enter urban airspace for safe operation, among which air route planning is a fundamental component of air route network design. Currently, most of the research on aircraft path planning is performed in free airspace, lacking the analysis and processing for the complex operation environment, which has led to the high risk and large operation cost of path planning results, failing to meet the demand for safe and efficient development in the future. Aiming at the above problems, eVTOL-oriented air route planning research was carried out. Firstly, the urban low-altitude airspace structure was planned, and the operational levels of eVTOL were clarified; this was followed by introducing the urban dynamic air–ground risk factors and constructing a dynamic risk assessment model containing risk level information; finally, the improved A* algorithm based on the risk cost was employed to plan the eVTOL air route network, which finally realized the purpose of short path length and low total risk. The simulation results showed that the route generated by the improved A* algorithm could reduce the risk cost by at least 30% with a relatively small path cost, which ensured the operation efficiency and safety of eVTOLs and laid the foundation for the further sustainable and green development of urban airspace in the future.

Exploring the Regional Structure of the Worldwide Air Traffic and Route Networks

The topological structure of the world air transportation network has been the subject of much research. However, to better understand the reality of air networks, one can consider the traffic, the number of passengers, or the distance between flights. This paper studies the weighted world air transportation network through the component structure, recently introduced in the network literature, by using the number of flights. The component structure is based on the community or multiple core-periphery structures and splits the network into local and global components. The local components capture the regional flights of these two mesoscopic structures (dense parts). The global components capture the inter-regional flights (links between the dense parts). We perform a comparative analysis of the world air transportation network and its components with their weighted counterparts. Moreover, we explore the strength and the s-core of these networks. Results display fewer local components well delimited and more global components covering the world than the unweighted world air transportation network. Centrality analysis reveals the difference between the top airports with high traffic and the top airports with high degrees. This difference is more pronounced in the global air network and the largest global component. Core analysis shows similitude between the s-core and the k-core for the local and global components, even though the latter includes more airports. For the world air network, the North and Central America-Caribbean airports dominate the s-core, whereas the European airports dominate the k-core.

Structure, Resilience and Evolution of the European Air Route Network From 2015 to 2018

In spite of the dynamic nature of air transport, air route networks, i.e. the backbone used to organise aircraft flows, are expected to be mostly static, with small changes occasionally being introduced to improve the efficiency and resilience of the system. By leveraging a large data set of European flights comprising years 2015 to 2018, we analyse its structure and evolution from the perspective of complex networks, with the aim of firstly describing it, and secondly to confirm its static nature. Results depict a highly dynamic system, with major topological changes happening at the end of 2017. Peripheral links are usually more vulnerable, due to the lack of effective reroutings, as well as central regions; additionally, the overall resilience of the network is almost constant throughout time, in spite of an increase in traffic. We further test several hypotheses regarding the design considerations driving such evolution. Beyond specific operational insights, these results highlight the importance of taking into account the evolution of this network in the study of traffic flows.

Hybrid Air Route Network Simulation Based on Improved RW-Bucket Algorithm

The fixed-route network is the basis for airlines to carry out flight direction planning. Some countries and regions have introduced temporary routes as a supplement to the fixed route structure. Temporary routes have the advantages of intercepting curves and straightening, and less detouring areas, which can save airlines fuel consumption and improve operational efficiency. This article takes the mixed airline's route network as the research object. Firstly, the structural properties of mixed air route networks are analyzed by using complex network theory. Secondly, the RW-bucket algorithm to generate a mixed air route network structure is analyzed. According to the conclusion of the analysis, the RW-bucket algorithm is improved. Finally two flight information region route network data are used to verify the proposed hybrid route network construction method by computer simulation.

Recent Research Progress of Unmanned Aerial Vehicle Regulation Policies and Technologies in Urban Low Altitude

With the rapid expansion in the number of Unmanned Aircraft Vehicles (UAVs) available and the development of modern technologies, the commercial applications of UAVs in urban areas, such as urban remote sensing (RS), express services, urban road traffic monitoring, urban police security, urban air shows and so on, have increased greatly. However, most UAVs, especially light and small civil UAVs, have been operating in low-altitude airspace, and a conflict may exist between increasing the number of UAVs and the limited low airspace. To promote low-altitude airspace resource development and to standardize the operation and management of UAVs in urban regions, some global laws and regulations and key technologies for urban low-altitude applications of UAVs have been implemented. This paper reviews the development of current policies and key technologies concerning safe and efficient operations of the light-and-small civil UAVs in low altitude in urban areas. Discussions are made progressively on measures and methods of airspace restriction, airspace structuring and air route planning in China primarily and the rest of world. After surveying the practical industry tests and the initial studies of air routes, the survey results indicate that the construction of air route networks is a scientific and effective measure to standardize and improve the efficiency of low-altitude UAV operations. From the view point of safety and efficiency, the most valuable direction for UAV regulation in urban regions involves deepening the research which largely relies on urban RS and Geographic Information System (GIS) technology, and application demonstrations of low-altitude public air route networks.

Network Robustness of Major Asian Airlines and the Impact of Airports’ Brokerage Roles

This study aims to evaluate the network robustness of major Asian airlines and to explore which airport types have the greatest impact on robustness. We also analyze airports’ specific brokerage roles and their impacts on the robustness of the entire air route network. We select 10 major Asian full-service airlines that operate the main passenger terminals at the top-ranked hub airports in Asia. Data is collected from the Official Airline Guide passenger route dataset for 2017. The results of the network robustness analysis show that Air China and China Eastern Airlines have relatively high network robustness. In contrast, airlines with broader international coverage, such as Japan Airlines, Korean Air, and Singapore Airlines have higher network vulnerability. The measure of betweenness centrality has a greater impact on the robustness of air route networks than other centrality measures have. Furthermore, the brokerage role analysis shows that Chinese airports are more influential within China and Asia but are less influential globally when compared to other major hub airports in Asia. Incheon International Airport, Singapore Changi Airport, Hong Kong International Airport, and Narita International Airport play strong “liaison” roles. Among the brokerage roles, the liaison role has a greater impact on the robustness of air route networks.

Regional disparity and driving forces of CO2 emissions: Evidence from China's domestic aviation transport sector

•We estimate China domestic air passenger market's CO2 emissions in 2007 and 2014.•We assess the change of air route networks and emission features focused on regional disparity.•Applying decomposition method to identify the driving forces of estimated CO2 emissions.•Noteworthy offset to increasing CO2 emissions is indicated from modal split changes.

Identifying influential waypoints in air route networks based on network agglomeration relative entropy

Air route network (ARN) is one of the most important transportation networks and the key waypoints (nodes) have significant influence on the stability and robustness of the ARN. In this paper, a network agglomeration relative entropy centrality (NAREC) method to identify influential nodes in ARNs is proposed, based on the network agglomeration and relative entropy theory. The basic topological features of the regional ARNs in Beijing, Shanghai and Guangzhou are analyzed and then the proposed method is applied to identifying influential nodes in the three networks. At last, the effectiveness of the NAREC method is demonstrated by the susceptible-infected-removed (SIR) model and the Kendall's tau coefficient. Results show that the proposed method is applicable and effective.

A measure of identifying influential waypoints in air route networks.

As the basic carrier of air flight operation, air route network (ARN) is of great significance to the smooth operation of flights. However, the waypoint is a core part of the route, so it is an important topic to identify influential waypoints in ARN. In this paper, a method to identify the influence of the node in ARN based on an improved entropy weight (IEW) method is proposed. Then, centrality measures including degree, closeness, betweenness and eigenvector as the multi-attribute of ARN in IEW application. IEW method is used to aggregate the multi-attribute to obtain the evaluation of the influence of each waypoint. To demonstrate the effectiveness of the IEW method, three real ARNs are selected to conduct several experiments with susceptible infected recovered (SIR) model. The results show the efficiency and practicability of the proposed method.

Analysis of flight conflicts in the Chinese air route network

The increase in economic exchange, brought about by globalization and leaps of progress in science and engineering, has led to a sharp increase in air traffic density. As a consequence, airspace has become increasingly crowded, and limitations in airspace capacity have become a major concern for the future development of air travel and transportation. In this paper, we adopt methods of network science to analyze flight conflicts in the Chinese air route network. We show that air conflicts are distributed heterogeneously along the waypoints of the Chinese air route network. In particular, the frequency of flight conflicts follows an exponential distribution. The time-space investigation of flight conflicts shows that they are concentrated at specific regions of the Chinese air route network and at specific time periods of the day. Our work offers fascinating insights into one of the world's largest and most busiest air route networks, and it helps us mitigate flight conflicts and improve air traffic safety.

Heuristics of node selection criteria to assess robustness of world airport network

The world airport network (WAN) is one of the networked infrastructures that shape today's economic and social activity, so its resilience against incidents affecting the WAN is an important problem. In this paper, the robustness of air route networks is extended by defining and testing several heuristics to define selection criteria to detect the critical nodes of the WAN. In addition to heuristics based on genetic algorithms and simulated annealing, custom heuristics based on node damage and node betweenness are defined. The most effective heuristic is a multi-attack heuristic combining both custom heuristics. Results obtained are of importance not only for advance in the understanding of the structure of complex networks, but also for critical node detection.

Newly established airlines developing processes and changing patterns of its air route in China

Abstract The Civil Aviation Administration of China (CAAC) started to open commercial airlines sector to private, collective and foreign capitals in 2004. From 2004 to 2007, 14 airlines were given approval to operate domestic passenger flights, which brought researchers a vital chance to investigate the performance of local state-owned airlines or private airlines in aviation sector. The study purposes of this paper are (1) to review the development process of these newly established airlines, and (2) to examine their air-route networks’ change patterns. The results show that, generally, the airlines have been re-constructing its air-route networks over those years. High-speed rail (HSR) operation is one of key elements to explain the change patterns. The study results are useful for aviation policy makers, airlines stockholders, and capitals interested in Chinese aviation market.

Effective local dynamic routing strategy for air route networks

With the rapid development of air transportation, network service ability has attracted a lot of attention in academe. Aiming to improve the throughput of the air route network (ARN), we propose an effective local dynamic routing strategy in this paper. Several factors, such as the routing distance, the geographical distance and the real-time local traffic, are taken into consideration. When the ARN is in the normal free-flow state, the proposed strategy can recover the shortest path routing (SPR) strategy. When the ARN undergoes congestion, the proposed strategy changes the paths of flights based on the real-time local traffic information. The throughput of the Chinese air route network (CARN) is evaluated. Results confirm that the proposed strategy can significantly improve the throughput of CARN. Meanwhile, the increase in the average flying distance and time is tiny. Results also indicate the importance of the distance related factors in a routing strategy designed for the ARN.

Using computational intelligence for large scale air route networks design

Due to the rapid development of air transportation, Air Route Networks (ARNs) need to be carefully designed to improve both efficiency and safety of air traffic service. The Crossing Waypoints Location Problem (CWLP) plays a crucial role in the design of an ARN. This paper investigates this problem in the context of designing the national ARN of China. Instead of adopting the single-objective formulation established in previous research, we propose to formulate CWLP as a bi-objective optimization problem. An algorithm named Memetic Algorithm with Pull–Push operator (MAPP) is proposed to tackle it. MAPP employs the Pull–Push operator, which is specifically designed for CWLP, for local search and the Comprehensive Learning Particle Swarm Optimizer for global search. Empirical studies using real data of the current national ARN of China showed that MAPP outperformed an existing approach to CWLP as well as three well-known Multi-Objective Evolutionary Algorithms (MOEAs). Moreover, MAPP not only managed to reduce the cost of the current ARN, but also improved the airspace safety. Hence, it has been implemented as a module in the software that is currently used for ARN planning in China. The data used in our experimental studies have been made available online and can be used as a benchmark problem for research on both ARN design and evolutionary multi-objective optimization.

Hub-and-spoke Construction Study of Air China

With the reform and development of the civil aviation industry in China, the three major group airlines, Air China,China Southern and China Eastern Airlines, were recomposed in the year 2002. The new composition of the threemajor Group Airlines represents the market competition of civil aviation industry has entered a new period.Based on the air route theory and the air route development of Air China, this paper conducts a deep analysis ofthe hub air route construction of Air China Beijing through the following two points: A systematic research into thepresent air route networks of Air China, which provides a necessary foundation for future research into the air routenetworks of the company; Discussing the hub air route networks of Air China in detail based on the marketbackground and competition analysis of the present air route networks.

Air Route Capacity Models

Three simple air route capacity models arc developed. The first model is based on the assumption of a common average speed of aircraft. This model gives a quick, rough estimate of an air route capacity. The second model is based on the assumption that overtaking of one aircraft by another is not allowed. This model gives the minimum capacity of a route. The third model is based on allowance for a certain maximum number of overtakings. This model gives a relatively more realistic estimate of the air route capacity. The models are intended as preliminary design aids for planners and designers of air route networks.