Airport Capacity Consequences Leveraging Aviation Integrated Modelling (ACCLAIM)

Airport capacity expansions are among the most contentious policy decisions. Proponents for adding runway capacity point to the multiple economic benefits occurring at local, regional, and national levels. The converse is also correct—capacity constraints may lead to increases in airfares and changes in airline networks that take transit and origin-destination traffic away from the region, thus limiting growth in air traffic and the economy. In contrast, opponents to capacity expansions argue that unrestricted capacity growth would impact those living around airports via increased noise and reduced air quality, and the wider population via its contribution to climate change.

Currently, the world’s air transportation system experiences airport capacity expansion projects with a combined value in excess of $500 billion. However, there does not exist any tool that would rigorously evaluate the associated local, regional, and global-scale trade-offs. Building upon the Aviation Integrated Modelling (AIM) tool, the aim of the ACCLAIM project is to enhance the AIM tool to assess a wide range of implications from capacity expansion projects at any airport in the world. The ACCLAIM model will capture the complex relationships between airport capacity, technology, operational and fleet change and passenger demand in the short-, medium- and long-term, while dealing with the complex interplay of uncertainties at each level.

ACCLAIM’s key objectives for the refined and expanded model are to provide an independent capability:

• To model how competing airline alliances will respond to capacity constraints at any airport in the world over the short-, medium- and long-term via changes in airfares, flight frequency, use of equipage, and network structure.
• To model how passengers will respond to changes in airline supply, taking into account airfares; airport, airline, and itinerary choice; airline loyalty programs; etc., given other prevailing trends in the air transport sector such as the increasing share of low-cost airlines and the development of very long-range aircraft.
• To establish how the airline and passenger response to airport capacity constraints will interact to affect the wider airport and its hinterland in terms of economic impacts (accessibility, trade, tourism, etc.), environmental effects (noise, air quality, and climate impacts) and their associated costs, along with the economic costs of delaying airport capacity expansion (by quantifying lost passenger demand).
• To quantify how uncertainties at each point in the system impact system level outputs, including uncertainties in inputs (e.g., future income levels; fuel prices, as also related to biofuel adoption), business models (e.g., the prevalence of low-cost long-haul carriers), available equipment (e.g., long-haul aircraft), etc.

ACCLAIM further expands the already existing AIM capabilities of

• modeling the integrated fleet level impact of new and changed aircraft and engine technologies, operational practices and fleet turnover in terms of environmental and economic performance, and
• testing the system level effects of options for change in national or international regulation or fiscal and charging policy.

While the tool to be developed is applicable to any airport worldwide, it will be applied initially to the London airport system, where the UK Government plans to add capacity in the near future.

ACCLAIM is a joint project between University College London, Imperial College London, and the University of Southampton with inputs from the aviation sector, government, and NGOs. The three-year project, which started in the fall of 2015, is funded by the UK Engineering and Physical Science Research Council (EPSRC).