The photo shows an aerial view of the Federal Highway Administration’s J. Sterling Jones Hydraulics Research Laboratory at the Turner-Fairbank Highway Research Center, which includes various flumes, pumps, and instrumentation for conducting applied and exploratory advanced research to improve prediction of flooding-related damages and design guidance.
Highways are designed and built to be resilient, but they are constantly tested by changing climate and extreme weather events such as hurricanes, blizzards, floods, and heat waves. Gradually and sometimes suddenly, temperature and storm forces take a toll on transportation infrastructure.
So how and to what degree is climate change factored into the design and construction of roads, bridges, and tunnels? What methodologies are being developed to identify vulnerabilities and implement management and adaptation strategies?
Such questions encouraged 12 members from the Forum of European National Highway Research Laboratories (FEHRL), an international association engaged in road engineering research and related topics, to visit the United States for a series of meetings focused on highways and climate change. Based in Brussels, FEHRL provides a coordinated structure for the interests of more than 30 European national research and technical centers, and other associated institutes from around the world.
FEHRL and the Federal Highway Administration (FHWA) have formed a strategic alliance to address highway transport challenges. In July 2011, FHWA and FEHRL signed a Memorandum of Cooperation (MoC) to establish a business protocol to optimize collaboration. The MoC sets forth a strategy for working together that offers the possibility of extending the reach of resources and enhancing the quality of research products.
On March 26, 2012, representatives of FEHRL visited FHWA’s Turner-Fairbank Highway Research Center (TFHRC) to hear about current research, adaptation issues, policy activities, sustainability evaluation and planning, and infrastructure performance. Martin Lamb, a regional manager at the Transport Research Laboratory’s office in Wales, presented an overview of the tour that would include subsequent discussions with the North Jersey Transportation Planning Authority, the New York City Climate Change Adaptation Task Force (PlaNYC), and the Louisiana Transportation Research Center. FEHRL Secretary General Steve Phillips and FHWA Office of Asset Management Director Butch Wlaschin also accompanied the tour. The FEHRL members represented 9 countries: Australia, Denmark, France, Germany, Israel, Norway, Slovenia, Sweden, and the United Kingdom.
Michael Trentacoste, Associate Administrator for Research, Development, and Technology (RD&T) and Director of TFHRC, welcomed the members, offered an overview of the facility, and highlighted key areas of research related to climate change. “We have a number of initiatives underway that are looking at different databases and integrating information that could help us better understand the impacts of climate change,” he said. “The road inventory data that we get from State departments of transportation (DOTs) and our own national bridge inventory data could help us in this area. There are a lot of databases that currently exist that could be integrated for a richer inventory of information.”
Marcus Auerbach of the German Federal Highway Research Centre (BASt) discussed the status of climate change adaptation research. He described the challenges facing roads in both Europe and Australia, which include extreme events such as storms, floods, and fires. He also discussed more subtle changes such as the lowering of the water table, and highlighted FEHRL’s Forever Open Road (FOR) program for climate resilience, which allows for appropriate levels of highway service under extreme conditions. FOR includes advanced technologies, such as those used in FHWA’s Exploratory Advanced Research program, as well as more readily implementable solutions.
Rob Kafalenos and Becky Lupes, air quality specialists and members of the Sustainable Transport and Climate Change Team, presented an overview of FHWA’s climate change adaptation activities, which are focused on delivering information and outreach, as well as developing and promoting the use of tools, methodologies, and applications.
“Past weather patterns and climate data is no longer a reliable guide for the future,” said Kafalenos. “We cannot assume that future rates of change will match the past. At the same time, we cannot precisely predict future change.”
FHWA is investigating the potential impacts of global sea level rise on transportation infrastructure and the effects of regional climate change. It is also organizing peer exchanges and workshops with the American Association of State Highway and Transportation Officials (AASHTO), State DOTs, and Metropolitan Planning Organizations.
“We expect to see an increase in the frequency and intensity of extreme weather as we move through this century,” added Kafalenos. “By 2100, the average intensity of tropical storms and hurricanes is projected to increase by 2 to 11 percent.”
In 2010, FHWA completed a vulnerability and risk assessment conceptual framework focused on developing an inventory of infrastructure assets; gathering climate data; assessing asset vulnerability and risk in relation to projected climate change; and analyzing and prioritizing adaptation options.
“We’re currently using the lessons learned from our pilot studies to update our conceptual framework,” explained Lupes. “The idea is to take some of this case study data and integrate it into a body of knowledge. One change is that the framework will be represented as a series of modules rather than a linear flow chart. We hope to deploy this on our Web site and add to it as we conduct additional pilots down the line.”
FHWA funded several vulnerability pilot studies, including projects in California, Hawaii, New Jersey, and Virginia. The Agency is also investigating impacts of climate variability and change on transportation systems and infrastructure in the Gulf Coast. The studies aimed to assist State DOTs and metropolitan planning organizations in advancing adaptation and assessment activities. They also offered FHWA an opportunity to test its climate change vulnerability and risk assessment framework.
“We’ve learned that the types of infrastructure that are considered critical vary by region, and the process of identifying what is critical is often politically sensitive,” added Lupes. “You have to consider community priorities as well as standard metrics.”
Joe Krolak, a principal hydraulic engineer at FHWA, recognized that accepting the status quo on bridge performance is not a wise decision, either when considering climate change or other events. To illustrate this, he described situations in 2004 and 2005 where hurricanes caused the failure of many bridges. “Neither State DOTs nor FHWA had sufficient information and guidance about how to protect bridges from future events,” he said. “It was clear the status quo would not be sufficient.”
So in a manner similar to adaptation strategies and approaches, “we needed to achieve a clearer focus, objective, and direction in protecting our coastal bridges,” he added. “How could we leverage the state of the practice? How could we best use the science and forensics we have on hurricanes?”
One way, Krolak suggested, was initiating a set of studies, technology transfer activities, and policies that could address wave force, storm surge, and scour vulnerabilities in existing and new structures. FHWA and AASHTO worked together on a multidisciplinary task force comprised of structural, coastal, hydraulic, and geotechnical experts to address and move forward on technical issues, design specifications, and implementation measures. “We had to look at this on a case to case basis,” said Krolak. “But given our limited staff and resources, the most cost-effective approach was to elevate our coastal bridges.”
The experience helped inform FHWA on programmatic and technically robust approaches to address such issues. “We did not intend to apply adaptation strategies, but in hindsight, we likely backed into them,” said Krolak.
In the afternoon, the FEHRL members toured FHWA’s Accelerated Load Facility (ALF), the J. Sterling Jones Hydraulics Research Laboratory, and the Aerodynamics Laboratory. These laboratories are advancing key research that could help the highway community better prepare and respond to climate change.
The ALF is a full-scale pavement tester that can apply a life cycle of traffic loading in a matter of months. It is used by pavement and highway research engineers to evaluate the durability of both new and existing pavement materials and to help develop smoother and more cost–effective highway systems. The facility can validate Superpave binder tests, mixture tests, and performance prediction models for rutting and fatigue cracking. Through a wheel assembly that models one-half of a single truck axle, it applies a load ranging from standard legal limits to heavy vehicle axels.
The Hydraulics Laboratory offers a way to test the hydraulic performance of highway drainage structures and stream crossings, including the hydraulics of bridges, culverts, and storm sewers. Researchers are currently conducting applied and exploratory studies to improve flooding prediction and provide design guidance for mitigating impacts on bridges and other hydraulic structures.
Focused on solving hydraulic and stream stability problems attendant to highways, the newly expanded laboratory will feature the first high-speed sediment recirculation flume in the United States. The flume was donated to the laboratory by the Florida DOT and designed after a high-speed flume in Auckland, New Zealand. It can be used to conduct live bed scour tests, which simulate the movement of riverbed material in water flowing upstream of a river crossing.
“The flume provides FHWA with a huge opportunity to conduct tests that are closer to actual field situations and expand the state of the knowledge,” said Kornel Kerenyi, a hydraulics research engineer who manages the lab. “This will result in more accurate design methods and procedures.”
Harold Bosch, a research structural engineer, manages the Aerodynamics Laboratory, which is used to study complex interactions between wind and bridges or other highway structures. “We have two wind tunnels,” he said. “We do laboratory and experimental testing, as well as physical modeling. We conduct full-scale studies, where we do benchmark testing and monitor structures over a period of time.”
The Aerodynamics Laboratory is the only wind tunnel facility in the United States that is dedicated solely to the study of wind effects on transportation structures. Researchers are charged with evaluating new designs, investigating performance problems of in-service structures, developing retrofit solutions, and establishing the aerodynamic properties of structures and structural components.
“Most structures will move or vibrate in response to the wind,” explained Bosch. “If vibrations occur at a certain amplitude, or occur often enough, they can cause fatigue or deterioration and shorten the life of a structure.”
Exploring fundamental wind engineering problems and developing new design guides, specifications, and more effective experimental procedures and simulation methods are also part of the work. “In our prediction models, we are working to establish methods for evaluating mitigating treatments,” observed Bosch. “We’re looking at whether it makes sense to change the shape of a structure or add strength to a structure or add other elements that could make it more compatible with the wind.”
At end of the day, the FEHRL members seemed pleased with their visit to TFHRC and satisfied with their understanding of the research. “The FEHRL team is happy with the U.S. contributions,” FEHRL Secretary General Steve Phillips said. “We have a lot to learn from each other. It was also important to highlight that our common search for solutions—Europe and the United States—cannot be limited to only the highway sector. We must also consider areas experiencing similar challenges, such as the coastal and offshore sectors addressed here. There are a lot of synergies to follow-up on.”
To read FEHRL’s article, “FHWA welcomes 12 FEHRL members on first day of US Scanning Tour,” please visit http://www.fehrl.org/index.php?m=33&a=content&id=649 For more information about international research coordination and collaboration efforts, contact Debra Elston, (202) 493-3181, email@example.com.