My work in the field of transportation and aviation began while I was a Ph.D. candidate at the University of California, Berkeley. My dissertation work was motivated by how high fuel prices–from either fuel price spikes or environmental policy–would impact the intercity transportation systems. My research developed optimization and empirical models to examine how fuel prices affect vehicle choice and scheduling. This research helped shape my current research program as a professor of Civil and Environmental Engineering in which I focus on methodological, empirical, and policy-oriented research to support a transportation system robust enough to withstand future challenges. I blend my background in statistics, operations research, and transportation policy to develop best practices for meeting challenges such as managing networks during irregular operations and determining the best way to allocate scarce airport capacity.
Ultimately, my goal is to forward academic research while developing implementable algorithms that transportation agencies, operators, and policymakers can use to analyze future changes to the system. To do so I use data in unique ways—for example, creating datasets of public and private data to answer questions about fuel consumption that we have been unable to address thus far (such as the potential of Air Traffic Management to reduce fuel consumption). I also develop mathematical optimization models that describe the system in new ways, but I focus on preserving the analytical nature of the model—the result being that we can look at the relationships between the variables, rather than always needing to collect data.
Megan Ryerson and Mark Hansen visiting the Delta Airlines Operations Center, where they plan and respond to changing weather conditions.
Megan Ryerson and Mark Hansen visiting the Delta Airlines Operations Center, where Delta plans and responds to changing weather conditions.
Research Areas
Fuel, the Environment, and Intercity Transportation The impact of high fuel prices on the transportation system is a major area of research interest for me. We are in an era of uncertain and high fuel prices (i.e. the fuel price spike of 2007-2008 when the price of fuel more than doubled, and the possible inclusion of aviation in the European Union Emissions Trading Scheme). The need to reduce fuel is multifaceted: reducing costs will increase the health of the transportation system and reducing Greenhouse Gas emissions ensures the health of our environment.
I am involved in multiple research avenues related to fuel consumption. One is ensuring that fuel models produce accurate predictions of fuel consumption. Modeling aviation fuel consumption is a critical component in decision making for all aviation stakeholders. Our ability to direct investments or policies towards cost and fuel efficiency is only as strong as our ability to model how fuel is consumed in practice. I investigate how the fuel calculations of different models compare with fuel consumed in practice. To enable this research, I utilize data from Delta Airlines through our research partnership. I have investigated fuel consumption models such as PIANO (Project Interactive Analysis and Optimization) and models built by the Federal Aviation Administration.
I am also interested in strategies to reduce fuel consumption from intercity transportation. I investigate the role of NextGen and Air Traffic Management technologies in reducing aviation fuel consumption. Additionally I am interested in the role of HSR in reducing intercity transportation fuel consumption, and research the actions of airlines in response to HSR implementating and the resulting fuel consumption change.
Reducing Transportation Network Vulnerability Natural disasters and acts of terrorism introduce “irregular operations,” or a sudden change to the planned system. Examples of short-term disruptions include terrorism and resulting security and weather events. The terrorist attacks on the United States of September 11, 2001 were a tragic example of how terrorism can paralyze an entire transportation system. Natural disasters have played a large role in causing localized network outages. The 2010 eruptions of Iceland’s volcano Eyjafjallajökull demonstrated how a single natural environmental event can cause a major hub in the aviation system, London Heathrow, to stop its operation for a period of days. The aviation system is particularly vulnerable to irregular operations due to its most basic characteristics: time-critical passengers and freight moving at high speeds on a hub and spoke network directed by a strict schedule. If an outage occurs at a hub airport, passenger and goods transferring at the impacted hub will be impeded unnecessarily; such an outage highlights the vulnerability of the transportation network. In my research I study the potential of using alternative hubs in an ad-hoc manner to reduce network vulnerabilities.
Aviation Demand Management Air transport demand – passenger demand for service and airline demand for operations– has grown rapidly in recent decades. Despite a traffic decline precipitated by the recession in the second half of the first decade of the 21st century, Federal Aviation Administration projections show traffic levels recovering by 2012 followed by a 30 percent growth by 2025. The FAA has plans to meet some of the demand increase through the development of additional runways; however, by their own estimates, this increase in infrastructure will not be sufficient to meet all the demand at many congested airports. I am investigating different means to manage current demand and policy implementation to utilize existing capacity most efficiently.
Select Research Grants
“Reducing Transportation Network Vulnerability,” Howard H. Baker Jr. Center for Public Policy at University of Tennessee, Knoxville, 2012, (Co-PI with Hyun Kim of University of Tennessee, Knoxville). ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- “Synthesis on Environmental Assessment of Air and High Speed Rail Corridors,” Airport Cooperative Research Program of the National Academies, 2012-2013, (Co-PI with Mikhail Chester of Arizona State University). ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- “Airport System Capacity Planning Study: Demand Management,” Landrum and Brown and the Port Authority of New York and New Jersey, 2011-2012, (PI). ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- “Ad-hoc Hubbing for Goods Movement in an Emergency Evacuation,” Southeastern Transportation Center, 2011-2012, (PI).
Ryerson, M.S., Hansen, M. 2013. Optimal Intercity Transportation Services with Heterogeneous Demand and Variable Fuel Price. In press, IEEE Systems Journal. DOI: 10.1109/JSYST.2013.2249213 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- Ryerson, M.S., Kim, H. 2013. Integrating Airline Operational Practices into Passenger Airline Hub Definition. In press, Journal of Transport Geography, Volume 31, pp. 84–93. -----------------------------------------------------------------------------------------------------------------------------------------------------------------------Ryerson, M.S., Hansen, M. 2013. Capturing the Impact of Fuel Price on Jet Aircraft Operating Costs with Engineering and Econometric Models. Transport. Res. Part C: Emerging Technologies, Volume 33, pp. 282–296. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- Ryerson, M.S., Hansen, M. The Potential of Turboprops for Reducing Aviation Fuel Consumption. Transport. Res. Part D: Transport and Environment, Volume 15, Issue 6, August 2010, pp. 305-314. ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- Complete list of Publications
