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Climate Change Adaptation Guide for Transportation Systems Management, Operations, and Maintenance

II. Context and Rationale for Adapting to Climate Change

A. Federal Highway Administration Action on Climate Change

Federal Highway Administration (FHWA) recognizes that climate change and extreme weather events pose a significant challenge to the safety, reliability, effectiveness, and sustainability of the national transportation system. In 2014, FHWA issued a directive that establishes FHWA policy on preparedness and resilience to climate change and extreme weather events, in compliance with Executive Order 13653, Preparing the United States for the Impacts of Climate Change, issued in 2013. The FHWA directive provides several ways in which “FHWA will integrate consideration of the risks of climate change and extreme weather event impacts and adaptation responses, into the delivery and stewardship of the Federal-aid and Federal Lands Highway programs,” including encouraging State DOTs, MPOs, tribal governments, and others to develop cost-effective strategies to minimize climate and extreme weather risks.3

FHWA began activities to address climate change in the early 2000s with several white papers followed by in-depth studies on the impacts of both climate variability and climate change in the Gulf Coast as well as sea level rise on the Atlantic Coast. FHWA’s next steps to address climate change were to develop tools and information that could be used by State DOTs and MPOs to assess their vulnerabilities to climate change. FHWA also continues to analyze strategies that can help improve resiliency. For additional information on FHWA’s climate change efforts, see FHWA web page "Summary of FHWA Climate Adaptation Initiatives."4

The FHWA Order and ongoing research activities are intended to promote transportation system resiliency, defined as the ability to anticipate, prepare for, and adapt to changing conditions and withstand, respond to, and recover rapidly from disruptions. Much of the work to date has been focused on assessing vulnerabilities and considering transportation infrastructure and design adaptation. This guide specifically focuses on how agencies can reframe TSMO and maintenance programs to increase resilience to the uncertainty and variability associated with climate change.

B. What is Transportation System Management and Operations and Maintenance?

This guide focuses on two primary transportation functions: 1) transportation systems management and operations and 2) maintenance. These functions both involve the day-to-day activities that maximize the use of transportation infrastructure. TSMO refers to an integrated approach of programs, projects, or services designed to get the safest and most efficient use out of existing and planned infrastructure. TSMO functions include traffic management, traffic incident management, traveler information services, traffic signal coordination, transit priority/integration, freight management, work zone management, planned special event management, road weather management, and active transportation and demand management.

Maintenance activities help to preserve and extend the use of transportation infrastructure and aim at carrying out day-to-day protective and repair measures to limit degradation due to natural processes (e.g., weather) or imposed processes (e.g., traffic). Maintenance functions include pavement management, shoulder maintenance, bridge inspection, vegetation management, road weather management, work zone management, and asset management.

C. How are Extreme Weather Events and Climate Change Related?

It is important to understand how extreme weather events and climate change are related and how they differ.5 Changes in climate and weather are linked over the long term, but no single weather event can specifically be attributed to a changing climate.

  • Weather events are defined as the state of the atmosphere in a particular location at a particular time. For example, rain, temperature, and wind are all aspects of local weather. “Extreme weather events can include significant anomalies in temperature, precipitation and winds, and can manifest as heavy precipitation and flooding, heatwaves, drought, wildfires and windstorms (including tornadoes and tropical storms).”6
  • Climate change refers to any significant change in the measures of climate lasting for an extended period of time. Climate change includes major variations in temperature, precipitation, or wind patterns, among other environmental conditions, that occur over several decades or longer. Changes in climate may manifest as a rise in sea level, as well as increase the frequency and magnitude of extreme weather events now and in the future.7

Long-term trends in climate are not dependent on any single extreme event. A single large rain event or even a single wet year may just be a normal fluctuation in weather patterns but changes that are noted year after year, such as a run of wet years, can be attributed to a larger change in the climate.

Climate change could mean that what was historically a rare weather event becomes increasingly frequent (possibly shifting from rare to occasional or regular). Consideration of how we respond effectively or not to the rare extreme events occurring today can provide useful information about how we can and should respond to increasing future risk. Optimizing for today’s extreme weather events makes our systems more prepared for the increased frequency of some events that is anticipated under a changing climate. Figure 3 demonstrates the shift in temperatures towards more hot weather and a slight decrease in cold weather.

On a left to right scale of cold, average, and hot, a bell curve representing the previous climate shifts to the right, indicating a new climate with increased probability of a shift in temperatures towards more hot weather and more record hot weather combined with the elimination of cold weather.
Figure 3. Graph. Weather Probability Distribution Showing an Increase in Mean Temperature.8

D. How Will Climate Change Affect Transportation System Management and Operations and Maintenance?

As climate changes, agencies may have to deal with new weather stressors that require different planning approaches or responses (e.g., loss of permafrost in Alaska, snow and ice control in Southern states). The 2011 report Adapting Transportation to the Impacts of Climate Change State of the Practice provided an overview of the operational impacts associated with climate change.9 These operational impacts include:

  • Increase in traffic incident management activities.
  • Road and lane closures.
  • Reduced (and variable) speed limits.
  • Disruption of transit service.
  • Road and transit diversions.
  • Truck restrictions.
  • Work zone management (to accommodate additional lane closures).

The 2013 report, Planning for Systems Management & Operations as part of Climate Change Adaptation, provides a summary of the anticipated changes to system maintenance (e.g., inspection, frequency of repairs, need for “quick maintenance” patrols); system operations practices and strategies (e.g., more frequent diversion to more robust alternate routes); travel behavior (e.g., motivation to use alternate modes of transport such as transit, biking, or walking); and freight transportation (dynamic or seasonal restrictions for trucks or rail during times of high heat) needed or likely to occur as a result of anticipated impacts of climate change.10

While TSMO and maintenance programs are often reactive by nature, the accelerating pace and increasingly unpredictable nature of extreme weather events could place increasing strain on an already stressed system. Further, agencies may not be optimized for the present; some practices need to be improved now.

TSMO and maintenance programs will need to take a proactive approach to regularly reevaluate existing programs and practices in light of new information and criteria (e.g., if preparing for new demands, they may need to adjust budgets) to ensure they are climate resilient. Opposition to making changes in operations may exist due to the risk-averse environments under which many State DOTs operate. Traditionally, this risk aversion has resulted in slow changes in practices and protocols in order to avoid changing what works. Transportation agencies could be at greater risk, however, if they do not change their practices rather than if they do. The environment in which they work is changing due to climate change; risk-averse decision makers should seek to avoid risks by considering climate change in their systems management and maintenance rather than ignoring it.

E. Why Do Transportation System Management and Operations and Maintenance Programs Need to Adapt to Climate Change?

TSMO and maintenance have vital roles to play in adapting to climate change. For many of the already observed and anticipated weather events related to climate change, TSMO and maintenance workers as well as the DOT emergency responders with whom they coordinate—who are, in some instances, DOT maintenance staff—are and will be the public face and the front-line of the response. Climate change presents a business risk for transportation agencies. Without proactive steps to anticipate potential changes and respond to them, the ability of agencies to support their core mission could be compromised. With climate change comes uncertainty, be it in a greater variability of expected events or unexpected extreme weather. By not understanding the risk or not assessing the vulnerability of their operations, agencies can be caught off-guard by an unexpected event leading to significantly degraded capabilities when they are most needed.

Changes in relatively short duration extreme events often result in the most significant consequences, and while DOTs may be prepared to respond to these events on an individual basis, the cumulative impact of more severe and more frequent events may warrant a change in business practices. Longer term changes to annual or seasonal averages, which are often cited in broad-scale summaries of projected climate change, cause less immediate impacts but over time can affect practices and costs.

Not all the necessary adjustments to business practices are radical; there are many ways—big and small—to account for climate change and reduce this business risk. In fact, many TSMO and maintenance adaptations will be the “low hanging fruit” to prepare DOTs for climate change, in contrast to changes to infrastructure design.

Incremental steps toward a more comprehensive program that fully considers how to incorporate potential climate change impacts will be easier for most agencies to manage than an immediate, full-fledged, comprehensive overhaul of their existing programs. A phased implementation approach will enable agencies to adapt their TSMO and maintenance programs to climate change in a planned and systematic manner. For this to occur, it is necessary to incorporate the needs of climate change and extreme weather events into the routine policy and practice of TSMO and maintenance at transportation agencies.

Adapting TSMO and maintenance programs is largely about improving capability rather than a major technology development and deployment initiative. Many of the technology elements used to support safety, congestion mitigation, and traveler information objectives are already in place and there is more on the way. For example, today Road Weather Information Systems (RWIS), cameras, and other roadside infrastructure are used extensively by agencies around the country. In the near future, connected vehicle technologies promise to overcome the barriers of fixed infrastructure and data availability. To adapt to climate change then, agencies need to consider how these existing capabilities need to evolve to meet the new and emerging requirements of a changing climate. These may take the form of hardening the communication links or rethinking the siting of these detection systems. Similarly, other existing processes for supporting safety and reliability need to be reviewed and supplemented to account for climate change.

F. Capability Maturity Framework

The American Association of State Highway and Transportation Officials (AASHTO) and FHWA have developed a capability maturity framework (CMF) to help DOTs adapt their TSMO programs.11 The CMF defines six areas of capability that form the supportive foundation for the implementation of TSMO strategies. As agency capabilities increase from ad-hoc implementation and planning to optimized practices, agencies will be able to have repeatable processes that are scalable, sustainable, and mainstreamed.

This guide aligns those actions needed to adapt TSMO and maintenance programs to climate change with the six areas of the CMF:

  • Business processes – including financial (e.g., budgeting) as well as conducting risk analyses and dealing with uncertainty, planning, programming, and standard operating/implementation procedures.
  • Systems and technology – transportation agencies have invested in a wide suite of technology and management systems to enable them to more efficiently manage weather events within their jurisdiction.
  • Performance measurement – including measures definition, data acquisition, analysis, and utilization.
  • Culture – including technical understanding, leadership, commitment, outreach, and program authority.
  • Organization and workforce – including organizational structure, staff capacity, development, and retention.
  • Collaboration – including internal collaboration and relationships with other public agencies and the private sector.

G. What's Already Being Done

The growing awareness that climate change can affect transportation has not yet resulted in widespread actions to identify and implement strategies to address climate change. Some transportation agencies have begun to assess vulnerability. Fewer have moved beyond vulnerability assessments and into adaptation planning. Even fewer have implemented adaptation strategies and begun to evaluate their effectiveness. Further, more emphasis to date has been on the implications of climate change for infrastructure planning, design, and engineering with less focus on system management, operations, and maintenance.

The transportation sector is not ahead or behind other sectors in this regard. Changes in climate are often discussed on a global or regional scale and presented with wide ranges of uncertainty and timescales. It is challenging to understand what climate change will mean on a local scale and for the timeframe most relevant to specific decision making processes of interest.

Transportation management, operations, maintenance, and emergency management professionals have the advantage, however, of a wealth of knowledge regarding how past extreme weather events have affected their systems and which solutions have been most effective in building resilience to those events. This knowledge will be immensely valuable in identifying which system impacts are likely to be experienced as a result of incremental climate change and possible solutions (i.e., adaptation strategies).

Case studies with real world examples are included throughout this guide. Readers can find “Examples from the Field” to provide insight into what other agencies have tried and learned from past efforts.

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3 FHWA, Order 5520, Subject: Transportation System Preparedness and Resilience to Climate Change and Extreme Weather Events, December 15, 2014. Available at: [ Return to note 3. ]

4 FHWA, "Summary of FHWA Climate Adaptation Initiatives" Web page. Available at: adaptation/ongoing_and_current_research/summary/index.cfm. [ Return to note 4. ]

5 A good discussion of the linkage between extreme weather events and climate change can be found in: D. Huber and J. Gulledge, “Extreme Weather and Climate Change: Understanding the Link and Managing the Risk,” Science and Impacts Program (Arlington, VA: Center for Climate and Energy Solutions, 2011). Available at: [ Return to note 5. ]

6 FHWA Order 5520, December 15, 2014. “Transportation System Preparedness and Resilience to Climate Change and Extreme Weather Events,” Available at: [ Return to note 6. ]

7 Ibid. [ Return to note 7. ]

8 Peterson, T.C., D.M. Anderson, S.J. Cohen, M. Cortez-Vázquez, R.J. Murnane, C. Parmesan, D. Phillips, R.S. Pulwarty, J.M.R. Stone, 2008: Why Weather and Climate Extremes Matter in Weather and Climate Extremes in a Changing Climate. Regions of Focus: North America, Hawaii, Caribbean, and U.S. Pacific Islands. T.R. Karl, G.A. Meehl, C.D. Miller, S.J. Hassol, A.M. Waple, and W.L. Murray (eds.). A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research, Washington, DC. Available at: [ Return to note 8. ]

9 Transportation Research Board Special Task Force on Climate Change and Energy, Transportation Research Circular E-C152: Adapting Transportation to the Impacts of Climate Change State of the Practice 2011, June 2011. Available at: [ Return to note 9. ]

10 FHWA, Planning for Systems Management & Operations as Part of Climate Change Adaptation, FHWA-HOP-13-030 (Washington, DC, 2013). Available at: [ Return to note 10. ]

11 See the AASHTO “Transportation Systems Management and Operations” web page for more information: [ Return to note 11. ]

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