Robustness of the air transport network

This paper presents a methodology for the detection of critical airports (those whose isolation would cause the largest losses in network connectivity) in the global air transport network (ATN), based on simulating an attack on selected ATN airports using different adaptive selection criteria. The performances of several node selection criteria are compared, together with a new criterion based on Bonacich power centrality. The results show that most critical airports can be detected with an adaptive strategy based on betweenness centrality. The detection of such airports may help the development of contingency plans to develop an appropriate response to any airport closure.     

Cascading failures in airport networks

Cascading failure phenomena can appear in complex networks that distribute flows of information, people or goods, when flow going through nodes or edges exceeds the capacity of network nodes or edges. Cascading failure models from previous research are not adequate for airport networks, as flow is not continuous, and load has to be redistributed among close airports, rather than previously existing connections. With these constraints in mind, we have defined an algorithm to simulate the management of cascading failures in airport networks. We use the algorithm to evaluate the effectiveness of several selection rules of alternative departure and arrival airports to affected flights to reduce the impact of the cascading failure. We have applied the algorithm to the Oceanic Airport Network to assess the impact of several incidents. Results show that selection rules of arriving airports have significant impact in reducing the effect of incidents affecting central airports.     

Exploring the network structure and nodal centrality of China’s air transport network: A complex network approach

This paper uses a complex network approach to examine the network structure and nodal centrality of individual cities in the air transport network of China (ATNC). Measures for overall network structure include degree distribution, average path length and clustering coefficient. Centrality metrics for individual cities are degree, closeness and betweenness, representing a node’s location advantage as being directly connected to others, being accessible to others, and being the intermediary between others, respectively. Results indicate that the ATNC has a cumulative degree distribution captured by an exponential function, and displays some small-world (SW) network properties with an average path length of 2.23 and a clustering coefficient of 0.69. All three centrality indices are highly correlated with socio-economic indicators of cities such as air passenger volume, population, and gross regional domestic product (GRDP). This confirms that centrality captures a crucial aspect of location advantage in the ATNC and has important implications in shaping the spatial pattern of economic activities. Most small and low-degree airports are directly connected to the largest cities with the best centrality and bypass their regional centers, and therefore sub-networks in the ATNC are less developed except for Kunming in the southwest and Urumchi in the northwest because of their strategic locations for geographic and political reasons. The ANTC is relatively young, and not as efficient and well-developed as that of the US.     

Increasing the resilience of air traffic networks using a network graph theory approach

Air traffic networks are essential to today’s global society. They are the fastest means of transporting physical goods and people and are a major contributor to the globalisation of the world’s economy. This increasing reliance requires these networks to have high resilience; however, previous events show that they can be susceptible to natural hazards. We assess two strategies to improve the resilience of air traffic networks and show an adaptive reconfiguration strategy is superior to a permanent re-routing solution. We find that, if traffic networks have fixed air routes, the geographical location of airports leaves them vulnerable to spatial hazard.     

Analysis of the Chinese Airline Network as multi-layer networks

This paper encapsulates the Chinese Airline Network (CAN) into multi-layer infrastructures via the “k-core decomposition” method. The network is divided into three layers: Core layer, containing airports of provincial capital cities, is densely connected and sustains most flight flow; Bridge layer, consisting of airports in Tier 2 and Tier 3 cities, mainly connects two other layers; and Periphery layer, comprising airports of remote areas, sustains little flight flow. Moreover, it is unveiled that CAN stays the most robust when low-degree nodes or high flight flow links are removed, which is similar to the Worldwide Airline Network (WAN), albeit less redundant.     

Drivers of long-haul air transport route development

An analysis of long-haul routes identifies trends and patterns underlying their development. Five distinct perspectives: geography, regulation, manufacturers, passengers and airlines are taken to investigate the drivers of long-haul route development. From the insights gained it is inferred that the demand for long-haul aircraft is a complex function thereof, whereby long-haul routes are operated between cities with strong business and social connections as influenced by the dynamics of change and underlying geography.     

The fortunes of air transport gateways

The paper explores the idea that the fortunes of some gateway cities are changing as airlines use modern aircraft to respond to new market opportunities. It uses data on inter-city journeys between Australia and Asia to identify a hierarchy of gateway cities, and then shows how the connections between them has changed over the 2000–2013 period. Results show that secondary, and smaller, gateways in both Australia and Asia have played more important roles in passenger movements over this time. In Melbourne in particular, stronger growth in the demand for international travel in that city along with more use made of the smaller long-haul aircraft by airlines, has strengthened its role as a gateway city relative to Sydney. These results confirm that the geography of inter-continental air networks are changing which may have important implications for the air transport roles of some cities in the immediate future.     

A multivariate neural forecasting modeling for air transport – Preprocessed by decomposition: A Brazilian application

An artificial neural forecasting model is developed for air transport passenger analysis. It uses a preprocessing method that decomposes information to reveal relevant features from the data. It is found that neural processing outperforms the traditional econometric approach and offers generalization on time series behavior, even where there are only small samples.     

A conceptual business model framework applied to air transport

The adoption of business models in different sectors has been disseminated exponentially as a result of organizational strategies, allowing the identification and definition of paths to be followed, and enhancing capture and value creation for consumers and the enterprise. In the case of the air transport sector, specifically the airlines, the proposition of new business models can contribute to creating competitive advantage. This study develops a conceptual business model framework applied to air transport, which prioritizes key components identified in the literature for designing business models for airlines. With the exploration of different aspects of business models and the identification of the main models used by airlines, the results demonstrate the need for the adoption of new models in this sector.     

Measuring the vulnerability of public transport networks

In the last years, studies on the vulnerability of public transport networks attract a growing attention because of the repercussions that incidents can have on the day-to-day functioning of a city. The aim of this paper is to develop a methodology for measuring public transport network vulnerability taking the Madrid Metro system as an example. The consequences of a disruptions of riding times or the number of missed trips are analysed for each of the network links with a full scan approach implemented in GIS (Geographic Information Systems). Using real trips distribution, each link in the network is measured for criticality, from which the vulnerability of lines and stations can be calculated. The proposed methodology also makes it possible to analyse the role of circular lines in network vulnerability and to obtain a worst-case scenario for the successive disruption of links by simulating a targeted attack on the network. Results show the presence of critical links in the southern part of the network, where line density is low and ridership high. They also highlight the importance of the circular line as an element of network robustness.     

Investigations on the distribution of air transport traffic and CO2 emissions within the European Union

This study analyses the structure of air traffic and its distribution among the different countries in the European Union, as well as traffic with an origin or destination in non-EU countries. Data sources are Eurostat statistics and actual flight information from EUROCONTROL. Relevant variables such as the number of flights, passengers or cargo tonnes and production indicators (RPKs) are used together with fuel consumption and CO₂ emissions data. The segmentation of air traffic in terms of distance permits an assessment of air transport competition with surface transport modes.The results show a clear concentration of traffic in the five larger countries (France, Germany, Italy, Spain and UK), in terms of RPKs. In terms of distance the segment between 500 and 1000 km in the EU, has more flights, passengers, RTKs and CO₂ emissions than larger distances. On the environmental side, the distribution of CO₂ emissions within the EU Member States is presented, together with fuel efficiency parameters. In general, a direct relationship between RPKs and CO₂ emissions is observed for all countries and all distance bands. Consideration is given to the uptake of alternative fuels. Segmenting CO₂ emissions per distance band and aircraft type reveals which flights contribute the most the overall EU CO₂ emissions. Finally, projections for future CO₂ emissions are estimated, according to three different air traffic growth and biofuel introduction scenarios.     

Performance evaluation of China's air routes based on network data envelopment analysis approach

Air routes are among the most important elements of civil aviation transport. Airlines' operations are mainly dependent on the structure and layout of air routes. This paper first divides the production process of air routes into two stages, allocation and transport, based on air route operational characteristics. Then, two network data envelopment analysis (DEA) models are proposed to analyze the efficiency of the system, allocation, passenger transport, and freight transport of 477 air routes. The research result demonstrates that the different constraints on intermediate measure in the network DEA models do affect the air routes’ efficiency significantly; Most air routes have high allocation efficiency and passenger transport efficiency, while they have low freight transport efficiency. Furthermore, the efficiencies of 82 airports are also analyzed after aggregating the efficiencies of the air routes.     

Study of the topology and robustness of airline route networks from the complex network approach: a survey and research agenda

Communication via air routes is an important issue in a world organized around a web city network. In this context, the robustness of network infrastructures, e.g. air transport networks, are a central issue in transport geography. Disruption of communication links by intentional causes (e.g., terrorist attack on an airport) or unintentional (e.g., weather inclemency) could be crucial for countries, regions and even the airlines affected themselves. Policymakers and the management of airlines and alliances should be able to reduce the effects of such interruptions in order to ensure good communication through air transport (i.e., maximize the robustness of their network at a reasonable cost). The literature review of the study of air transport route networks through an analysis of complex networks has highlighted a lack of contributions to the study of the topology and the robustness of such networks which contrasts, with advances undertaken for other transport networks or communication systems. This survey suggests areas in which research should be undertaken, based on the existing literature in other areas and from three different perspectives: global route networks, airline alliances, airlines and airports so as to help towards a better understanding of air traffic and, therefore, to be able to assess the potential damage of any airport being inoperative for a continent, country or airline.     

CO2 emissions associated with hubbing activities in air transport: an international comparison

Hubbing is an important operational practice in air transport. Many studies have been conducted to examine the benefits and impacts of hubbing from an economic perspective. However, its impact on CO₂ emissions, especially across different air spaces, is not well understood. This paper explores the impact of hubbing activities in air transport from an environmental perspective. With a detailed methodology and data from the Greek and Hong Kong/Sanya flight information regions (FIRs), three levels of CO₂ emissions are estimated: airport-based, airspace-based and flight-based. After contrasting the CO₂ emission efficiencies of Athens International Airport (AIA) and the Hong Kong International Airport (HKIA), aircraft type and flight distance are examined to explain their emission efficiency differences. It is found that HKIA is associated with poorer CO₂ emission efficiency at the airport and airspace levels because of the larger aircraft and longer flight distance. However, when CO₂ emission efficiency at the flight level is considered, HKIA, with a higher passenger load factor, performs better. Major international hub airports should implement additional environmental measures to minimize the impact of hubbing activities on CO₂ emissions at the airport and airspace levels.     

An airline's management strategies in a competitive air transport market

Over the last decade, the demand for domestic and international flights in Korea has increased substantially. To meet the strong flight demands, several low cost carriers have begun to offer flight services. In addition, full service carriers have been motivated to establish their own subsidiary low cost carriers to maintain their market share against rival low cost carriers. This paper studies the management strategies of three kinds of airlines - full service carrier, its subsidiary low cost carrier and rival low cost carrier - based on game theory in the competitive air transport market. Each airline is assumed to act as a player and chooses strategies regarding airfare, flight frequency, and the number of operating aircrafts for specific routes while maximizing its own profits. Demand leakages between the airlines are considered in the flight demand function according to the selected strategies of all airlines. Through various game situations reflecting realistic features, this study provides managerial insights that can be applied in the competitive air transport market.     

Challenges to domestic air freight in Australia: Evaluating air traffic markets with gravity modelling

With two of the busiest air traffic corridors globally, Sydney-Melbourne (SYD-MEL) and Sydney-Brisbane (SYD-BNE), very liberal open skies agreements, and the world's most isolated large city in Perth, air freight in Australia should be destined for substantial growth, but has in contrast to other regions such as the US not yet materialised. This paper identifies challenges surrounding domestic air freight markets in Australia and compares the provision of road vs air freight services utilising gravity modelling methods. Our findings suggest the impedance of domestic air freight services in Australia is greater for regional areas between the primary cities (such as Canberra, between Sydney and Melbourne) than remoter areas (such as Cairns in Northern Australia). Our models show further that in addition to distance, air freight capacity on any of our analysed routes is despite being demand-pulled in terms of GDP dependency significantly attuned to factors at both the origin (in particular domestic trade capability, i.e. manufacturing and logistics) and destination.     

Differential pricing strategies of air freight transport carriers in the spot market

The single pricing approach fails to reflect different demand changes in response to its cargo space prices at different sales periods. This might be an obstacle to maximize the cargo space revenue of air freight carriers. This paper conducts the empirical analysis on pricing strategies in the spot market for two competitive air freight transport carriers operating on the same segment. It concludes that two carriers gain more revenues with the optimized differential pricing approach than with the single pricing approach. In theory, the research enriches the current literature in terms of pricing strategy optimization under the competition of two parties. In practice, it provides references for air freight transport carriers in their decision-making of applying the differential pricing strategy.     

The impact of the current economic crisis on the geography of air traffic volumes: an empirical analysis

This paper presents a comprehensive analysis of air services dynamics during the recent economic crisis. Through a regression analysis, we show that at the country scale, the change in the supply of seats is highly dependent on economic growth, confirming the cyclical nature of the air sector. Hence the crisis of air services has much more affected the USA, Europe and Japan than the rest of the world. However, many countries deviate from this general trend. In a second step, using the existing literature, we explain some of these deviating figures. National specificities and airline strategies seem to influence the intensity of the crisis. We argue that the intensity of the crisis in the US is due to the structural oversupply of the air sector. Through other cases, especially the Middle East, we show that hubbing strategies might reduce the impact of the crisis, or at least make it less dependent upon local economic dynamics. In contrast with other authors, we found no positive impact of the share of low-cost carriers on the supply during the crisis, despite their success in some specific contexts like between Europe and Morocco.     

Mode choice behavior analysis of air transport on the introduction of remotely piloted passenger aircraft

Remotely piloted aircraft (RPA) are expected to be applied to passenger aircraft; however there is a lack of research which analyzes choice behavior for RPA compared to conventionally piloted aircraft (CPA), in terms of socio-demographic characteristics. The purpose of this paper is to present a model for air travelers’ mode choice behaviors under the assumption that RPAs are introduced to the market. Results show that the fare of RPA should be lowered by a certain amount (i.e., discount factor of RPA) to compete with CPA, and the discount factor should be higher for older, female, and frequent travelers. The results also show that there are still concerns about RPA, and pilot on board is preferred. Through this study, it will be possible to predict the acceptance of newly introduced technology in consideration of socio-demographic characteristics of potential customers.     

Air passenger transport and economic activity

In the present paper we analyze whether a correlation exists between air passenger transport and economic activity at world level and for the various geographical areas of the world. Econometric models are calibrated and the coefficient of determination is calculated for each case. The whole analysis permits an estimation of a plausible evolution of air passenger transport activity and of its growth rates that can be expected.