Flooding was reported to be of the greatest concern to state DOTs (96 Percent), Followed by Extreme Snow and Ice Events (65 Percent), and Hurricanes or Tropical Storms (39 Percent).
Extreme weather events can disrupt transportation services, damage expensive infrastructure, result in more frequent maintenance and, in some cases, influence decisions when rebuilding. In 2013 in the U.S., there were nine weather and climate disaster events of a magnitude that resulted in more than $1 billion each in losses. Together, these events caused 123 deaths and $23 billion in damages.1
There is strong evidence that heat, heavy precipitation, and coastal flooding events will grow in frequency and severity in coming decades and we will likely continue to experience droughts and tropical storms. Changes in the frequency or intensity of extreme weather events also influence changes in transportation system operations and planning, risk-based asset management, construction, and design inputs or considerations for engineers.
For example, changes in weather-related stressors such as increased wind or storm exposure, wave impacts, temperatures, precipitation, and freeze-thaw cycles may induce states to review and/or modify values or parameters associated with the design of pavements, hydraulic features, sign and lighting structures, and other aspects of the transportation infrastructure. Similarly, how would one assess the risk to existing infrastructure from increased incidence of extreme weather events?
Extreme Weather-related Challenges
State DOTs play a key role in not only the response to and recovery from extreme weather events, but also in improved preparedness and resiliency of the transportation system. In a 2014 survey2 of state DOTs, the following common DOT challenges were noted:
- Concerns about the increasing frequency of unusual and extreme weather events, which drives the need for widespread sharing of resiliency and sustainability practices to promote efficient use of resources. State DOTs see benefit in peer exchange with other DOTs, metropolitan planning organizations (MPOs), transit organizations, and other transportation providers.
- Significant damage to assets and system disruptions as a result of extreme weather events.
- Difficulty managing state transportation infrastructure with existing state and federal funding constraints.
- Wide variation of changing weather patterns, impacts, consequences, and capacity for event recovery by state and location.
For challenges related to specific extreme weather event types, 96 percent of state DOT respondents reported flooding to be a high priority followed by extreme snow and ice events (65 percent) and hurricanes or tropical storms (39 percent).
Extreme Weather Events Symposium
In 2013, the American Association of State Highway and Transportation Officials (AASHTO) held a national Extreme Weather Events Symposium3 in Washington, D.C. that focused on the impacts of extreme weather events on transportation. It provided a platform for DOT staff from a variety of disciplines to convene and discuss DOT experiences and lessons learned from extreme weather events; trends and projections of extreme weather in the U.S.; costs of extreme weather events; and risk management strategies in design, operations, maintenance, asset management, and emergency response.
Case studies presented by the various DOTs covered major events like storms and flooding (New Jersey DOT, Minnesota DOT, District of Columbia DOT), wildfires and dust storms (Colorado DOT, Arizona DOT, Maryland DOT). In those case study presentations, common challenges included communications, equipment and material shortages, and the sheer size and impact of the unprecedented event. In many cases, post-event debriefings took place for discussion on changes and improvements to existing procedures and practices. As an example, the District of Columbia DOT (DDOT) instituted the following changes after the 2010 “Snowmageddon” event:
- One floating plow truck in every ward with a captain as a backup for rapid response to any concerns from the snow command center or the mayor;
- Improved training programs for drivers and supervisors, simulator training to enhance driver plowing skills, expanded anti-icing pre-treatment of residential streets using four small spray trucks procured last year;
- Improved cost accounting with the StormTrak4 system; and
- Contingency plans.
There has been a growing interest in discipline-specific resiliency information and case studies following extreme weather events. In the 2014 survey, 78 percent of respondents reported extreme weather and transportation systems management and operations (TSM&O) as a high priority topic. TSM&O includes: development and execution of contingency plans, evacuation and emergency route planning, traveler information, early warning systems, and pre-positioning of materials and equipment, among others.
As a follow-up to the 2013 Extreme Weather Events Symposium, the sponsors, with support from Parsons Brinckerhoff (now part of
Additionally, a “Top 10” list of suggestions and further resources was developed - through DOT interviews, case studies, project experience to date, and research recently completed or underway - to prepare practitioners in a specific discipline for extreme weather. Top 10 discipline-specific lists5 were available for: TSM&O, highway design, bridges and structures, construction, and maintenance. These updates and lists were distributed at the 11 regional and technical committee meetings across the country.
Although DOT experience with operations varies by state and topic, below is a sample “Top 10” list of suggestions for TSM&O managers and staff to better prepare for extreme weather:
- Have contingency plans for power outages, detours, debris clearance, and routing for overweight or disabled trucks - to include pre-approved contractors and funds.
- Operate effective evacuation routes in high-risk areas.
- Develop effective public and traveler information systems/services to inform travelers of travel options (including social media tools, mobile apps, and collecting real time conditions through vehicle technology).
- Use response to “routine emergencies” to test staffing, deployment, and communications. Also, coordinate in advance with partners at the local, state, and federal level in the event response is required.
- Develop strategies for responding to transportation system disruptions due to weather-related events, including pre-positioning replacement materials (culverts, etc.) in vulnerable areas.
- Prepare backup communications such as satellite phones, portable highway advisory radios, truck radios, and alternative networks.
- Identify facility locations vulnerable to risks (flooding, landslides, etc.), and develop appropriate strategies to minimize such risk.
- Incorporate “early warning indicators” for potential extreme weather-related risks into asset and maintenance management systems.
- Prepare for events with backup power generators, “hardened” sign structures and traffic signal wires, pre-positioned variable message sign boards, and support vehicles trucks.
- Protect workers from extreme temperatures and weather during day-to-day and response activities.
Available Resources for State Dots
AASHTO’S Resilient and Sustainable Transportation Systems (RSTS) Technical Assistance Program
This program provides timely information, tools, and technical assistance to state DOTs to manage challenging issues associated with extreme weather events, infrastructure vulnerabilities, energy demands, and diminishing resources. The technical assistance program6 was created in May 2008 at the request of AASHTO members. AASHTO established a steering committee comprising various state DOT commissioners, secretaries, and directors to oversee the fee-based technical assistance program. Initially, the program was designed to respond to states’ growing interest in transportation-related emissions reductions and to explore opportunities for state DOTs to participate in alternative fuel initiatives, provide increased travel options, and prepare for and respond to increased impacts of climate change.
Since 2008, the technical assistance program has sponsored a number of program activities to provide technical and policy support to the states. In addition to the 2013 Extreme Weather Event Symposium mentioned above, examples include:
- Member-Only News: A bimonthly newsletter that includes extreme weather event special reports featuring DOT case studies and lessons learned based on first-hand interviews with DOT officials.
WSP | Parsons Brinckerhoff, in partnership with Bloomberg BNA, conducts the interviews and publishes the regular newsletter. Additional newsletter features include information on recent projects, programs, state practices, and technical information on responding and adapting to extreme weather events, and strategies for reducing energy consumption. Breaking news alerts on executive orders, funding announcements, or newly proposed legislation related to extreme weather and energy are also provided to members.
- President’s Task Force on Climate Preparedness and Resiliency (March 2014): AASHTO, with support from WSP | Parsons Brinckerhoff, assisted the Vermont Agency of Transportation (VTrans) in collecting and synthesizing information on state DOT resiliency efforts to inform transportation sector recommendations for the President’s Task Force on Climate Preparedness and Resiliency.
- Website: The AASHTO Transportation and Climate Change Resource Center provides information on recent developments, links to resources, successful state DOT practices, and webinars developed through the program. Design, maintenance, and forthcoming improvements are made possible with technical support by WSP | Parsons Brinckerhoff in partnership with Bloomberg BNA.
- Webinars (2010-2012): In 2010 and 2011, WSP | Parsons Brinckerhoff developed and conducted 12 webinars for AASHTO, providing useful information to state DOTs on reducing energy consumption. In 2012, AASHTO hosted a webinar on best practices and challenges related to infrastructure adaptation.
- Electric Vehicle Publication (July 2011 – March 2012): The technical assistance program supported the development of the publication “An Action Plan to Integrate Plugin Electric Vehicles with the U.S. Electrical Grid”.
- Research, Policy Support, Stakeholder Coordination
The technical assistance program has evolved over time to provide assistance on a range of topics. Most recently, and as evidenced in the above examples, the program has expanded its focus to creating more resilient transportation systems in the face of increasingly frequent extreme weather events.
1The National Oceanic and Atmospheric Administration’s National Climatic Data Center: Billion-Dollar Weather/Climate Disasters.
2The survey was conducted through the American Association of State Highway and Transportation Officials (AASHTO) Resilient and Sustainable Transportation System (RSTS) Technical Assistance Program with support from Parsons Brinckerhoff.
3The meeting was sponsored by AASHTO’s Resilient and Sustainable Transportation Systems (RSTS) Technical Assistance Program, in coordination with the Center for Environmental Excellence (CEE) by AASHTO and the Federal Highway Administration (FHWA).
4StormTrak is a web-based system enabling the tracking of snow and storm operations costs. It provides a complete history of all operational activities, decisions, costs and details for each event which has proven to be invaluable when preparing documentation for FEMA reimbursements or other expense justifications. Tracking categories include but are not limited to: employee attendance (regular hours worked, overtime, double time and any union differential), contracted drivers, and government vehicles deployed.
5To view the complete set of discipline-specific handouts on extreme weather and the transportation system, please visit: http://environment.transportation.org/center/products_programs/conference/2014_extreme_weather_sessions.aspx
6Formerly known as Sustainable Transportation: Energy, Infrastructure, and Climate Solutions (STEICS).