Megan S. Ryerson

Landing on empty: estimating the benefits from reducing fuel uplift in US Civil Aviation

Airlines and Air Navigation Service Providers are united in their goal to reduce fuel consumption. While changes to flight operations and technology investments are the focus of a number of studies, our study is among the first to investigate an untapped source of aviation fuel consumption: excess contingency fuel loading. Given the downside risk of fuel exhaustion of diverting to an alternate airport, airline dispatchers may load excess fuel onto an aircraft. Such conservatism comes at a cost of consuming excess fuel, as fuel consumed is a function of, among other factors, aircraft weight. The aim of this paper is to quantify, on a per-flight basis, the fuel burned due to carrying fuel beyond what is needed for foreseeable contingencies, and thereby motivate research, federal guidance, and investments that allow airline dispatchers to reduce fuel uplift while maintaining near zero risks of fuel exhaustion. We merge large publicly available aviation and weather databases with a detailed dataset from a major US airline. Upon estimating factors that capture the quantity fuel consumed due to carrying a pound of weight for a range of aircraft types, we calculate the cost and greenhouse gas emissions from carrying unused fuel on arrival and additional contingency fuel above a conservative buffer for foreseeable contingencies. We establish that the major US carrier does indeed load fuel conservatively. We find that 4.48% of the fuel consumed by an average flight is due to carrying unused fuel and 1.04% of the fuel consumed by an average flight is due to carrying additional contingency fuel above a reasonable buffer. We find that simple changes in flight dispatching that maintain a statistically minimal risk of fuel exhaustion could result in yearly savings of 338 million lbs of CO2, the equivalent to the fuel consumed from 4760 flights on midsized commercial aircraft. Moreover, policy changes regarding maximum fuel loads or investments that reduce uncertainty or increase the ability to plan flights under uncertainty could yield far greater benefits.

Build Airport Capacity or Manage Flight Demand? How Regional Planners Can Lead American Aviation Into a New Frontier of Demand Management

Problem, research strategy, and findings: To address air traffic congestion, airports can manage flight demand or expand capacity; the Federal Aviation Administration (FAA) requires an environmental impact statement (EIS) to evaluate feasible alternatives to capacity expansion. The FAA also funds regional planning agencies to conduct optional regional aviation systems plans (RASPs). We study the extent to which airports investigate demand management in lieu of increasing capacity and if RASPs play a role in doing so. Of the 17 EISs for major airport capacity expansions between 2000 and 2013, only Boston (BOS), as influenced by the local RASP, fully assessed demand management. We find three barriers to airports evaluating demand management in their EISs: narrow project objectives, uncertainty over the FAAs stand on demand management, and economic development concerns. RASPs can help surmount these barriers because they are not constrained by the EISs narrow objectives and can comprehensively evaluate demand management alternatives. Takeaway for practice: Demand management in aviation, as in surface transportation, holds potential for cost and other savings. Strengthening the role of regional planners in the airport planning process would lead to greater consideration of demand management and may bring innovative solutions to airport congestion. We recommend: a) the FAA play a more direct role in funding regional aviation planning and creating regional aviation planning coalitions; b) regional planners collaborate early in the airport EIS process; and c) planners encourage the FAA to make demand management a mandatory alternative in an EIS for airport capacity expansion.

Building Air Service Sustainability: Analytical Approach to Documenting Air Carrier Incentive Programs in Airport Sustainability Plans

Airport operators occupy the complex space between managing a major economic generator for their region and operating a piece of municipal infrastructure that generates significant environmental emissions. Airport operators document airport environmental impacts and economic vitality and development, as well as study initiatives to improve in these areas in airport sustainability plans. However, neither airport sustainability planning guidance nor plans in practice document the economic or environmental impacts of air carrier incentive programs, which are municipal and airport-funded programs to waive fees for airlines launching new routes. As air carrier incentive programs (or airline incentive programs) are a mechanism through which airports and cities invest in growth and economic development while contributing to the environmental impacts of their airport, these programs are a natural fit for study within the structure of airport sustainability plans. This study presents a methodology for estimating the air traffic, investment costs, and environmental emissions from new flights launched under airline incentive programs and compares these values with existing economic development and sustainability initiatives documented in airport sustainability plans. It is found that the scope of airline incentive programs is significant in terms of air traffic, costs, and emissions, providing justification for documenting airline incentive programs. How a gap in the understanding of the economic value of incentivized flights hinders a comprehensive evaluation of airline incentive programs is discussed. The lack of a planning process for airline incentive programs keeps airport operators from learning from the experiences of their peers.

Incentivize It and They Will Come? How Some of the Busiest U.S. Airports Are Building Air Service With Incentive Programs

Problem, research strategy, and findings: In the 1990s, the Federal Aviation Administration (FAA) prohibited airport sponsors (local authorities managing airports) from diverting airport revenue to general municipal budgets and allowed the busiest airports to create air service incentive programs (ASIPs) to induce airlines to launch new air service. These incentive programs have not been evaluated, although planners need information on their long-term effectiveness. Few data, however, are available on ASIP programs; I created a database to identify which airports have ASIPs, which new airline services received incentives, and the services that continued after incentives ended. I find that 26 of 44 airports with ASIPs that recruited new routes spent

Better Pen-and-Paper Surveys for Transportation Research in Developing Countries: A Modified, Stated Preference, Pivoting Approach

171.5 million combined between 2012 and the first quarter of 2015, 40% on routes that were not retained when the incentive ended. The busiest airports in the largest cities with growing populations, relatively independent of local economic status, were most able to recruit and retain new airline services. Small and medium airports, particularly in stagnant areas, were not able to recruit and retain new air services. Takeaway for practice: The FAA should require airport sponsors to submit comprehensive information on their ASIP programs—the routes recruited and retained, as well as detailed estimates of the costs and benefits of each route—to provide planners with needed information. The FAA also should loosen the constraints on the use of non-aeronautical airport revenues so that communities can choose between spending on incentives to increase air service and other programs to increase local economic development.

Aircraft Rerouting due to Abrupt Facility Outages

In developing countries, the rapid pace of socioeconomic and technological change necessitates the use of quick-response survey methods. Transportation researchers often work with limited budgets in environments with relatively low rates of computer and Internet access. Such conditions can preclude the use of the computer-assisted survey methods that are preferred for conducting research in industrialized countries. This paper describes novel methods for low-cost and high-quality data collection in a data-poor environment. The context is a stated preference (SP) experiment to estimate adoption of bikeshare and electric bikeshare in Beijing, but the methods are transferable. Two main methodological contributions are described. The first is a unique survey design that allows SP pivoting to occur within a single pen-and-paper interview (PAPI). For small- to medium-sized surveys, this design is often more cost-effective than traditional pivoting methods that require either a multistage PAPI survey or computer-assisted interviews. The second contribution is the demonstration of the use of affordable GPS technologies and publicly available data for the purpose of survey protocol enforcement and quality control. The paper describes survey design features that are of particular value for nonmotorized or semimotorized transportation research.

Spatial Differences and Costs of Emissions at U.S. Airport Hubs.

Abrupt airport outages resulting from terrorism, natural disasters, and incidents can cause reroutes and fuel-critical situations for flights. Although aircraft carry reserve fuel for holding and diversions, poor situational awareness and incomplete information about conditions may cause disordered reroutes. In this paper a deterministic routing model for airport outages that assigns flights an arrival time at a diversion airport is developed. The model includes a parameter for decision time, allowing one to investigate the value of faster response with advanced technologies. The model minimizes flight time after the disaster to ensure that flights avoid fuel emergencies. Model formulations include an unconstrained allocation of flights to diversion airports and a constrained allocation of flights according to routing rules; this formulation is suboptimal but provides a powerful tool because of its potential ease of implementation. The models are used to determine how coordinated traffic flow management actions could have diverted flights and reduced fuel-critical situations immediately following the destructive 2011 Tωhoku earthquake. It is found that under reasonable assumptions about diversion airports and capacities, all flights can be accommodated without reaching a fuel-critical state for a decision occurring 20 min after the disaster. A longer diversion decision-making process results in some flights reaching emergency conditions, requiring the use of other, less preferred diversion airports and expedited handling procedures. The more constrained model requires faster response for full accommodation of flights.

Optimal Intercity Transportation Services With Heterogeneous Demand and Variable Fuel Price

As local governments plan to expand airport infrastructure and build air service, monetized estimates of damages from air pollution are important for balancing environmental impacts. While it is well-known that aircraft emissions near airports directly affect nearby populations, it is less clear how the airport-specific aircraft operations and impacts result in monetized damages to human health and the environment. We model aircraft and ground support equipment emissions at major U.S. airports and estimate the monetized human health and environmental damages of near airport (within 60 miles) emissions. County-specific unit damage costs for PM, SOx, NOx, and VOCs and damage valuations for CO and CO2 are used along with aircraft emissions estimations at airports to determine impacts. We find that near-airport emissions at major U.S. airports caused a total of

Airport Capacity Enhancement and Flight Predictability

1.9 billion in damages in 2013, with airports contributing between

Environmental Assessment of Air and High-Speed Rail Corridors

720 thousand and