As our climate-world around us changes, our infrastructure must change too. Year-after-year an increasing number of climate fueled catastrophes damage or destroy roads across the country. At what point do you stop rebuilding it, and just relocate?
Climate change impacts American’s lives daily and has increasingly caused the nation’s transportation infrastructure to face more frequent and unpredictable damage from severe weather events, notes Nancy Singer, Federal Highway Administration’s (FHWA) Office of Pavements.
Consider Skagit County, Washington where in July concrete panels under an asphalt road surface buckled due to searing temperatures.
The Alaska Department of Transportation and Public Facilities notes when dealing with ice-rich silty permafrost, ice wedges, or ice lenses, problems start when the thawing causes differential settlement, causing the ground – including roads – to settle, sink or move unevenly.
Its four strategies to manage the effects of permafrost thaw on infrastructure include:
Avoiding building on permafrost
Removing it by digging out the frozen material under the ground, replacing it with stable material
Using techniques to keep the ground frozen
Acknowledging the challenges inherent in those three options is to build over permafrost using traditional construction methods and accept the consequences
The American Society of Civil Engineers (ASCE) gives America’s roads a ‘D’ grade in its 2021 report card, with report cards issued every four years.
Among the many challenges noted is the impact on an increase in severe weather events, with rising temperatures estimated to add approximately $19 billion to pavement costs each year by 2040.
It’s important to create dedicated federal investments to build resilience into the nation’s road and bridge infrastructure and integrate resilience planning into State Transportation Asset Management Plans, the ASCE notes.
A decade ago, “resilience wasn’t really talked about,” notes Richard Willis, PhD, vice president, Engineering, Research & Technology for the National Asphalt Pavement Association (NAPA).
“It was fringe engineering, especially in the pavement space. NAPA really started putting resources into helping the industry understand it in 2019 and continues to try to help owners and contractors better understand the topic,” he says.
"From a roadway pavement perspective, there has been increasing awareness that there is a need to quantify the impact of climate change in engineering design and management processes,” says Singer.
FHWA notes federal statute does not limit the number of times funding can be provided for an area impacted by a disaster, provided the disaster is declared in accordance with federal agency program requirements.
State departments of transportation are required to consider alternatives when highways and bridges are repeatedly subject to repair and reconstruction due to emergency events, particularly when developing transportation plans and programs.
FHWA’s Emergency Relief Program supports the department’s priority of addressing climate change by providing funding to help states perform repairs following major natural disasters and extreme weather events, which increasingly are influenced by climate change.
A listing of fiscal year 2024 allocations for each state, the District of Columbia and Puerto Rico can be on the agency’s Federal-aid Programs and Special Funding site.
The Bipartisan Infrastructure Law also provides new programs and funding opportunities to help the U.S. transportation system be more resilient to climate change.
There is no specific threshold to evaluate the number of times or the cost to rebuild a roadway, says Singer.
“If the roadway meets Emergency Relief (ER) program criteria, then it is eligible for ER funding,” she adds. “FHWA encourages state DOTs to consider incorporating resilience betterments into facilities that have been damaged multiple times.”
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Areas most at risk
“Coastal areas are very concerned with sea level rise,” notes Willis. “If you are in Colorado, its resilience program also includes events like rockslides. California considers wildfires. Hawaii even considers impact of lava.”
Climate change impacts are geographically widespread due to differences in the nature of the hazard – hurricanes, flooding, mudslides, wildfires, and other catastrophic weather events – as well as topography and climate, says Singer, adding FHWA’s emergency relief allocations reflect that.
“For example, Hurricane Beryl, which has caused so much damage in Jamaica, Mexico and Texas, is thought to have been made worse by higher sea surface temperatures caused by climate change,” she notes.
As part of developing their federally required Hazard Mitigation Plans, states, some regional and local entities identify and rank their specific natural hazard risks. Several federal government agencies, state governments, some local governments, and private entities also maintain data for natural hazards risks of interest.
“Building more resilient transportation infrastructure can help our nation better withstand these impacts in the years to come,” notes Singer. “While FHWA’s Emergency Relief program reimburses states for the cost of repairs to roads and bridged damaged by natural disaster or catastrophic event, the PROTECT program funds projects designed to help states make transportation more resilient to withstand future events by making funds available for planning activities as well as construction projects.”
“This approach provides agency owners a mechanism for assessing vulnerability of roadways from disaster hazards and identifying adaptation options for building resilience,” says Singer.
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Planning ahead
Owners and contractors need to have a relationship and have a plan in place ahead of time, notes Willis.
He cites a road restoration project that was completed in seven days after a 7.0 magnitude earthquake hit Anchorage, Alaska on November 30, 2018.
Among the road damaged by rockslides and aftershocks was the northbound off-ramp of Minnesota Boulevard near Ted Stevens Anchorage International Airport.
The FHWA approved a quick release of $5 million in emergency relief funds to get the $7 million project into place to restore essential travel.
Obtaining the amount of asphalt needed to fix the earthquake-damaged roads against the backdrop of an already tight construction schedule and limited roads proved to be a challenge for the Alaska Department of Transportation & Public Facilities.
Agency staff called asphalt plant owners the day after the earthquake to alert them. A crew of 14 worked around the clock to haul out the rubble, bring in asphalt, then repave and paint the roads.
The department credited planning and training protocols for highway crews as a driving factor toward the rapid response and repair time.
A May 2023 ‘Pave it Black’ podcast Willis and Brett Williams, senior director, engineering & technical services for the NAPA recorded with Andy DeCreane, vice president of Ajax Paving Industries of Florida discussed the company’s task to rebuild the Sanibel Causeway weeks after Hurricane Ian hit Florida in 2022.
“Some people define resilience as the capacity to withstand or to recover quickly from difficulties, or toughness,” Willis notes. “Other definitions talk about adaptation and hardening and looking at recovery from a massive or traumatic event. In the world of pavements, we have to think about resilience as well. There are times when catastrophic events hit communities and they impact our roads and our abilities to connect people with each other.”
Ajax Paving Industries has a disaster recovery plan in place prior to the storm, establishing meeting places post-storm and assessing employees’ needs.
Everything at the asphalt facilities is strapped down. Silos are filled with aggregate for the weight so the wind doesn’t blow them over. Preparations include having enough generators, chainsaws, and diesel fuel on hand.
DeCreane says most Florida communities are prepared for hurricanes, adding the state’s transportation department “does a fantastic job of getting emergency contracts out early before the storms.
“It’s a matter of getting the roads open. You're not fixing the roads – you’re just cutting branches. You're getting everything out of the way. This allows people to get to where they need to be – emergency response.”
After that comes emergency road repair contracts.
Regarding the Sanibel Island Causeway destruction, “This particular area was cut off completely because the road was completely washed out,” says DeCreane. “With the D.O.T. and the designers, we were able to do a complete reconstruct kind of bridge abutment. The designer we hired had it done within two weeks. That was a big feat.”
With the D.O.T.’s roadway section washouts, “we could do more of a typical section with stabilized sub-grade base and a lot of asphalt base,” DeCreane says.
DeCreane says among lessons learned from past severe weather events is the importance of design work. Designers are taking a deeper look at Mechanically Stabilized Earth walls for bridge abutments, he adds.
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Factoring in previous failures when designing for future resilience
“These methods allow road builders to account for climate change and resilience in engineering design by generating alternatives, assessing how they would fare under future climate conditions, and considering costs and benefits,” says Singer.
Willis notes the biggest threat to infrastructure/roadway resiliency nationwide is a lack of a long-term and consistent funding mechanism.
“It may sound silly, but agencies can’t look at their system and make long-term plans when they don’t know how much money they are getting for more than five years out,” he says. “Preparing for and responding to disasters takes funds, and we need to be sure all agencies can strengthen what they have.”
“Climate change is a substantial threat to roadway resilience nationwide, affecting the reliability and capacity of our nation’s transportation system,” says Singer. “Typically, roadway pavement infrastructure is designed and managed assuming a stationary climate. We know this is not the case.
“Assuming climate stationarity in the design and management of pavements and other infrastructure could result in pavements that are under-designed for the environmental conditions they may experience over their service lives—such as heavy precipitation, flooding, heat waves, wildfires, sea level rise and storm surge—and lead to failure.”
Singer says going forward, “our nation will have to learn to build projects that strengthen the country’s surface transportation system including roads, bridges, and highways, against extreme weather events.
“By increasing the resilience of these assets, investments will reduce short- and long-term costs by minimizing future needs for maintenance and reconstruction.”
Roadway impacts caused by extreme weather events exacerbated by climate change merit changes in design and management processes to offset their vulnerability, Singer notes.
FHWA’sSynthesis of Approaches for Addressing Resilience in Project Development provides specific examples of how to incorporate resilience in the project development process for a range of assets (pavements, bridges, ports) and stressors (heat, flooding, etc.) through “engineering-informed adaptation studies” (FHWA 2017c).
Willis notes it’s important to start local.
“Understand the threats, the materials, the design procedures, and then work in partnership with industry to make it happen,” he says. “Agencies also need to better understand how to leverage local materials. Especially when rapid response is needed, agencies cannot wait on long hauls to get materials in place.”
FHWA and its partner agencies are joining together to address the issue of the impact of severe weather events on road repair costs as well as the economic impact from disrupted travel, as outlined here.
Funding provided under FHWA’s Emergency Relief program at a national scale continues to be significant, representing the magnitude of the impacts of climate change, notes Singer.
“FHWA has a range of reports, tools, and case studies focusing on the negative impacts of extreme weather and climate change on transportation, methods to assess vulnerability to these threats, and strategies to address in developing highway projects,” she adds.
In ‘Leveraging SETS Resilience Capabilities for Safe-to-Fail Infrastructure under Climate Change’, the authors note safe-to-fail approaches for infrastructure planning and design improve the capacity of cities to adapt for uncertain climate futures by identifying social, ecological, and technological systems (SETS) capabilities to prepare for potential failure scenarios.
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