On the multi-dimensionality and sampling of air transport networks

Complex network theory is a framework increasingly used in the study of air transport networks, thanks to its ability to describe the structures created by networks of flights, and their influence in dynamical processes such as delay propagation. While many works consider only a fraction of the network, created by major airports or airlines, for example, it is not clear if and how such sampling process bias the observed structures and processes. In this contribution, we tackle this problem by studying how some observed topological metrics depend on the way the network is reconstructed, i.e. on the rules used to sample nodes and connections. Both structural and simple dynamical properties are considered, for eight major air networks and different source datasets. Results indicate that using a subset of airports strongly distorts our perception of the network, even when just small ones are discarded; at the same time, considering a subset of airlines yields a better and more stable representation. This allows us to provide some general guidelines on the way airports and connections should be sampled.

Applying complexity science to air traffic management

Complexity science is the multidisciplinary study of complex systems. Its marked network orientation lends itself well to transport contexts. Key features of complexity science are introduced and defined, with a specific focus on the application to air traffic management. An overview of complex network theory is presented, with examples of its corresponding metrics and multiple scales. Complexity science is starting to make important contributions to performance assessment and system design: selected, applied air traffic management case studies are explored. The important contexts of uncertainty, resilience and emergent behaviour are discussed, with future research priorities summarised.

A framework for evaluating the European airline costs of disabled persons and persons with reduced mobility

In recent years, airlines have been servicing a greater variety, and increasing numbers, of disabled persons and persons with reduced mobility (PRMs), particularly associated with ageing, obesity and medical needs. With the quantity of PRMs likely to increase in the future, there will be a growing impact on the airlines' associated actual and opportunity costs, about which there is minimal literature and data. Therefore the aim of this paper is to identify standard functional key factors (FKFs) with which airlines could audit their PRMs costs, and which could be used by other interested bodies, such as governments, when considering relevant aviation policy. These FKFs are related to nine areas, namely PRMs’ transfers; mobility aids; aircraft delays/diversions costs; staff training costs; staff health, safety and welfare; aircraft fixtures and equipment costs; airport costs; transaction costs; and opportunity costs. Further research is needed to obtain the data for these FKFs.

ADR in aviation: European and national perspectives

The air transport sector generates the largest share of cross-border consumer complaints, as a proportion of complaints received by the ECC-Net. Since the foundation of the ECC-Net in 2005, air passenger claims have made up around one fifth of the total caseload most years. A pan-European framework of bodies that handle consumer to business disputes will be implemented through the consumer ADR directive.4 Taking these developments into consideration, the aviation industry is an interesting sector to study. This paper looks at dispute resolution for air passengers in the United Kingdom (UK) and Germany, as well as at European level.

Factors affecting airport route development activity and performance

Airports have become increasingly active in route development as a means of attracting, growing and retaining air services. However, little is known about the different levels of route development activity at airports, or the extent to which route development activity affects performance. Based on the findings of a survey of 124 airports worldwide, this study finds that larger airports are significantly more active than smaller airports. It also finds that private airports are more active than public airports, and that airports in Europe are more active than airports in other world regions, although differences according to ownership and location are not significant. Route development activity has a significant positive effect on performance. Factors associated with the airport business environment (market turbulence, competitive intensity, market growth and airport constraints) were not found to have a significant moderating effect on the relationship between route development activity and performance. However, two factors were found to have a significant direct effect on performance; market growth has a significant positive effect while airport constraints have a significant negative effect.

The paradox of competition for airline passengers with reduced mobility (PRM)

Airline competition with customer service as product differentiator has forced down costs, air fares and investor returns. Two passenger markets operate in aviation: (a) able-bodied passengers for whom airlines compete and (b) passengers with reduced mobility (PRMs) – disabled by age, obesity or medical problems – for whom airlines do not compete. Government interference in the market intended to protect a minority of narrowly-defined PRMs has had unintended consequences of enabling increasing numbers of more widely-defined PRMs to access complimentary airline provisions. With growing ageing and overweight populations and long-haul travelling medical tourists such regulation could lead to even lower investors’ returns. The International Air Transport Association (IATA) (2013) examined the air transport value chain for competitiveness using Porter’s (2008) five forces but did not distinguish between able-bodied passengers and PRMs. Findings during an investigation of these two markets concurred with IATA-Porter that the markets for the bargaining powers of PRM buyers and PRM suppliers were highly competitive. However, in contrast to the IATA conclusions, intensity of competition, and threats from new entrants and substitute products for PRM travel were low. The conclusion is that airlines are strategically PRM defensive by omission. Paradoxically, the airline which delivers the best PRM customer service could become the least profitable.

The paradox of competition for airline passengers with reduced mobility (PRM)

Airline competition with customer service as product differentiator has forced down costs, air fares and investor returns. Two passenger markets operate in aviation: (1) able-bodied passengers for whom airlines openly compete and (2) passengers with reduced mobility (PRMs) – disabled by age, obesity or medical problems – for whom airlines do not compete. Government interference in the market intended to protect a minority of narrowly-defined PRMs has had unintended consequences of enabling increasing numbers of more widely-defined PRMs to access complimentary airline provisions. With growing ageing and overweight populations and long-haul travelling medical tourists such regulation could lead to even lower investors’ returns. The International Air Transport Association (IATA) (2013) examined the air transport value chain for competitiveness using Porter’s (2008) five forces but did not distinguish between able-bodied passengers and PRMs. Findings during an investigation of these two markets concurred with IATA-Porter that the markets for the bargaining powers of PRM customers and PRM suppliers were ‘highly competitive’. However, in contrast to the IATA conclusions the threats posed by new entrants, substitute products and intensity of competition for PRM passengers were all ‘low’. The conclusion is that airlines are strategically PRM defensive by omission. Paradoxically, the airline which delivers the best PRM customer service could become the least profitable.

Politics vs economics: unintended consequences of Governments’ interventions in airlines’ markets

Overlaying theories of market inefficiencies and/or failure onto airline economics indicates that the industry encounters at least seven of the indicators which have triggered interventions by national, multi-national or supranational governments (NMSGs) trying to resolve political, social or environmental problems. The NMSGs’ interventions aimed to resolve lack of competition, fill missing markets, and neuter the presence of negative externalities, free riders, social inequalities and moral panic. Desk research showed that their interventions (many lacking preliminary economic analysis) either intentionally solved and/or unintentionally triggered market inefficiencies or failures. It is possible that some of the interventions could eventually make advanced world airlines subsidise their advancing world competitors.

Measuring the cost of resilience

Air traffic management research lacks a framework for modelling the cost of resilience during disturbance. There is no universally accepted metric for cost resilience. The design of such a framework is presented and the modelling to date is reported. The framework allows performance assessment as a function of differential stakeholder uptake of strategic mechanisms designed to mitigate disturbance. Advanced metrics, cost- and non-cost-based, disaggregated by stakeholder sub-types, are described. A new cost resilience metric is proposed and exemplified with early test data.

Low emission zones: the likely effects on the freight transport sector

London’s air quality has improved over recent decades, but is still the worst in the UK. Road transport emissions play an important part in this pollution. A low emission zone (LEZ) would help to accelerate the introduction of cleaner vehicles, and reduce the numbers of older, more polluting vehicles operating in London. The survey work carried out indicates that there is support among goods vehicle operators for an LEZ in London, depending on the precise scheme definition. Operators would generally try to comply with LEZ regulations, with most companies either using technical approaches to ensure that their London vehicle fleet complied with the required emission standard or by redeploying vehicles with the appropriate emission standard from other locations.

Low emission zones: the likely effects on the freight transport sector

London's air quality has improved over recent decades, but is still the worst in the UK. Road transport emissions play an important part in this pollution. A low emission zone (LEZ) would help to accelerate the introduction of cleaner vehicles, and reduce the number of older, more polluting vehicles operating in London. Survey results indicate that there is some support among goods vehicle operators for a LEZ in London, depending on the precise scheme definition. Operators would generally try to comply with LEZ regulations, with most companies either using technical approaches to ensure that their London vehicle fleet complied with the required emission standard, or redeploying vehicles with the appropriate emission standard from other locations.

The role of urban consolidation centres in sustainable freight transport

The paper reviews the study and use of urban consolidation centres (UCCs) which are a freight transport initiative intended to reduce goods vehicle traffic, vehicle-related greenhouse gas emissions and local air pollution. An international literature review has identified 114 UCC schemes in 17 countries (12 in the European Union (EU) and 5 outside the EU) that have been the subject of either a feasibility study, trial or a fully operational scheme in the last 40 years. The period from 2006 to 2010 has been the most active 5-year period in terms of UCC study, trial and scheme generation since the first UCC study was carried out in the early 1970s. Five countries account for the majority of all the 114 UCC schemes identified: France, Germany, Italy, the Netherlands and the UK. The vast majority of UCCs serve either all or part of an urban area. Examples of UCCs serving a single property (such as an airport or shopping centre) and construction sites have also been identified. Key organizational, operational, and financial issues that are critical to the success of UCCs are discussed. The traffic and environmental impacts of UCC trials and fully operational schemes are also reviewed.