Resiliency & Transportation Infrastructure

Resilience is an important objective of transportation agencies and those that fund them, and it is this objective that has them considering the effects of climate change the most. Resilience is defined by the US Federal Highway Administration as, “the ability to anticipate, prepare for, and adapt to changing conditions and withstand, respond to, and recover rapidly from disruptions”. BGC knows that the transportation sector recognizes that many threats are tied to the changing climate. Climate change processes and extreme weather represent stressors of increasing significance for transportation departments and railway companies. They already deal with closures, repairs, and other consequences from geohazard impacts and extreme weather on a regular basis. Exposure to geohazards and weather over the lifespan of an asset drives deterioration and decline in performance. As climate change increases the frequency and magnitude of many geohazards and extreme weather events, we are seeing the cumulative effects of these hazards accelerate the deterioration process for many transportation assets.  

Recent observed climate change impacts continue to highlight the need for more resilient transportation infrastructure. The July 2021 Glenwood Canyon debris flows in Colorado, which occurred over the burn area from the 2020 Grizzly Creek Fire, was triggered by summer storms with intense rainfall. This resulted in the full closure of a segment of the I-70, a major interstate, for almost two weeks, followed by a one-lane reopening and months of repair. In November 2021, atmospheric rivers in the Pacific Northwest greatly impacted southern British Columbia and northwestern Washington State. The atmospheric rivers caused extensive damage along major transportation corridors, which at one point were so severe that they completely cut all of Vancouver and its surrounding areas off from the rest of Canada. 

Each time an event occurs as the result of climate change processes, transportation agencies must respond quickly to get infrastructure back up and running as soon as possible. “Build back better” programs are common in communities devastated by extreme climate events. Improving infrastructure resilience promises to do this, but the ‘how’ is still in question. Will up front investments yield desired performance in the future? 

The threat of climate change impacts is challenging for transportation agencies to manage, given budget limitations and a large backlog of improvement projects from infrastructure that are currently not meeting performance standards. The American Society of Civil Engineers (ASCE) 2021 US Infrastructure Report Card found that 43% of public roadways are in poor or mediocre condition, 42% of bridges are at least 50 years old, and 7.5% of bridges are structurally deficient. The 2019 Canadian Infrastructure Report Card states that 16.4% of roads and 12.4% of bridges and tunnels are in poor or very poor condition. These statistics show that there are many pre-existing needs and deficiencies in the transportation sector, and it is expected that these needs and deficiencies are likely to grow as we continue to experience the effects of climate change. 

BGC understands that the demand for improving resiliency of transportation infrastructure from climate change processes comes from many groups, from governments to everyday commuters. In the US, the 2022 administration is pushing to improve climate change resiliency by investing in infrastructure. And in Canada, some provinces have issued requirements to consider climate change in transportation projects, but how it is executed is left up to the agency or engineer with guidance remaining limited.  

The general public is also advocating for climate change consideration in the design of roads, highways, and bridges. Public interest in the understanding of the impacts of climate change on infrastructure is demonstrated by the success of citizen science projects like ‘Catch the King’ Tide, a high tide flood mapping project run by the Virginia Institute of Marine Science.  

Building resiliency

The resilience of transportation systems can be viewed in the context of risk. Risk is the product of the likelihood of a hazard; the vulnerability of an asset, or the likelihood that it will suffer damage if impacted by a given hazard; the potential damage to the asset or users; and the likelihood that the hazard will impact the asset based on spatial-temporal conditions. Transportation infrastructure resilience can be improved by reducing the vulnerability of assets. 

BGC supports our clients to ensure resiliency of assets is top of mind on all of our projects. There are several methods to reduce the vulnerability of assets, such as building them stronger so they can withstand extreme loading conditions, or moving the asset out of the anticipated zone of impact. Climate change impacts on geotechnical design parameters for transportation projects are often difficult to predict or may be too subtle to reasonably incorporate in the design process. As a result, guidance for incorporating climate change into geotechnical design is often limited. Our experience in geohazards can help support this process and ensure the resiliency of your assets. 

Assessing & mitigating impacts

Climate hazard assessments are an important part of the planning process for transportation agencies who aim to improve resiliency of assets or reduce the likelihood of potential climate hazard impacts. Climate hazard assessments have been conducted by several US states to observe how changes in climate processes may impact transportation assets. Conducting these studies helps states identify corridors where climate and geohazard risk is the greatest and helps to develop risk-informed mitigation strategies. BGC recently completed one such study for the Colorado Department of Transportation and are positioned to assist future clients with these crucial assessments. 

Projects to mitigate impacts typically aim to reduce the likelihood or severity of impacts where climate change processes are expected to increase the frequency or magnitude of triggering events or increase the likelihood of hazards. Hazard assessments can also help prioritize slopes where transportation departments can use rockfall protection strategies. BGC’s geohazard risk assessment and management services to the transportation sector support our clients by helping them understand the links between climate and geohazard triggering and evaluating how climate change will affect geohazard risk along transportation corridors.  

Resilient asset management

Asset management systems, and in particular geo-asset management systems, are in the early stages of development across North America. BGC has many years of expertise and can help agencies reduce financial exposure within transportation systems. Asset management systems help transportation agencies identify where investments are needed, whether in maintenance, restoration, or reconstruction/replacement. Acting early to extend the life of these assets can add value and reduce large costs down the road. Climate change processes including warming temperatures, increased frequency and severity of rain and drought, fires, and flooding all cause additional stress to transportation corridors and can accelerate the deterioration process. We are here to help you assess the hazards posed by these processes by modeling and incorporating them into our asset management services. 

Emissions targets

The general focus of BGC’s work in the transportation sector is on providing reliable and efficient transportation systems, rather than on carbon footprint reductions, since carbon emissions have been implicit in the transportation sector for years. Currently infrastructure projects in Canada requiring Climate Lens assessments require evaluation and reporting of project-related carbon emissions. It is possible that these requirements could be expanded to a wider range of projects in the future. 

The transportation sector is responsible for a large portion of greenhouse gas emissions. In Canada, transportation is responsible for approximately 180 million metric tons of CO2 emissions per year, and in the US, 1,900 million metric tons of CO2 emissions per year (29% of total US emissions). There is significant interest from governments in reducing those numbers by improving public transit systems and increasing the percentage of electric vehicles on the roads. 

Transportation infrastructure construction and maintenance is also carbon intensive. Concrete structures, which are ubiquitous in transportation infrastructure systems, have a large carbon footprint as concrete production requires extremely high temperatures and releases carbon dioxide through chemical reactions. Heavy equipment used during construction also contributes to the carbon footprint of transportation systems. BGC’s expertise can help reduce these greenhouse gas impacts by considering efficient routes, alternatives to current construction methods, and design-to-build projects that are resilient from the start.

Supporting the transportation sector facing the effects of climate change

Climate change and resulting extreme weather events will continue and are projected to increase in frequency and severity in the future. We know that considering the resiliency of your transportation assets and the safety of its users are a key priority for many in the transportation sector. We are here to help you adapt by identifying the uncertainties and impacts associated with future loading conditions, which will support making better risk-informed decisions. BGC’s advanced skillset along with Cambio, our asset and geohazard management system, our geohazard risk assessment and mitigation work, and geophysics experience combine to provide the best-in-class support to our clients and future clients.  

BGC is dedicated to helping clients address climate change in their projects in ways that align with your priorities, budgets, and goals. Interested in hearing how? Contact our Climate Change Team.

Click here to explore our other Creating Resiliency articles.

Using lidar data to inform risk management decisions

In August 2020, the Grizzly Creek Fire ignited in the rugged Glenwood Canyon of central Colorado. Glenwood Canyon is considered one of the most scenic corridors on the U.S. Interstate Highway System and is a critical route for road and rail traffic across the state as well as providing recreation opportunities for hiking, biking, hunting, and river rafting. Over an approximate four-month period the fire altered forest lands along the steep canyon walls and forested connecting drainages above Interstate 70 (I-70) and the Colorado River.

The following winter provided a quiet recovery period for the canyon, but this was only temporary as the summer months in this region of Colorado generate intense thunderstorms with runoff that can overwhelm heathy drainages. Unfortunately following a forest fire, the storm runoff on burned and bare soils can be orders of magnitude more destructive. The summer monsoon season of 2021 was no exception, with several storms generating sediment laden post-wildfire debris flows that covered and damaged I-70 and the nearby Amtrak railway, deposited sediment in the Colorado River, and also stranded travelers in the canyon at times. The events resulted in weeks of highway closure for this critical corridor during the summer travel season, causing adverse economic impacts to nearby communities and measurable disruptions to interstate commerce.

Post-fire debris flow blocking the Colorado River.

To reduce the potential for future disruptions, the Colorado Department of Transportation (CDOT) engaged with BGC to understand how ground conditions are changing following the wildfire and 2021 post-fire debris flows. Through this additional understanding, CDOT can prioritize mitigation projects on the basis of greatest need and cost-benefit, while also advancing predictive models that consider the relationship between burned conditions, slope, changes in terrain, and precipitation thresholds that can lead to disruptive debris flows.

Debris flow deposition on I-70 bridge approach.

To measure continuous ground change over the entire burn area, BGC contracted with an aerial survey firm to collect and process airborne lidar for over 100 square miles (260 square kilometers) of the Glenwood Canyon and Grizzly Creek Fire area. This newly collected lidar data was processed against existing public lidar data collected in 2016. These two sets of lidar data were entered into Cambio, BGC’s software platform, to deliver an interactive lidar change detection layer across the entire burn area. This processing of change between two different lidar data sets uses a patent-pending change detection algorithm to calculate positive and negative change over this entire area. Using Cambio, this type of change detection processing can be turned around within 24 hours.

Cambio screenshot showing the ground movements following storms in the Grizzly Burn Area.

BGC continues to work with CDOT and other partner agencies, such as the United States Geological Survey, to understand how the Canyon slopes have changed after the fire and 2021 debris flow season, and to plan mitigation efforts that can be implemented in the summer of 2022 and beyond. A better understanding of the post-fire debris flow events in Glenwood Canyon may also help CDOT and other stakeholders understand their risk exposure to debris flow impacts from future burn scars.

The Geohazards paradigm is so different to what a lot of the other members of CDOT are used to being exposed to. It is often difficult to convey the severity of an event to people outside of the response, but Cambio is such a great tool to do this alongside the other utility it provides.

BEAU Taylor
Colorado Department of Transportation
Close-up Cambio screenshot showing measurement of sediment loss and deposition in the Blue Gulch Basin of Glenwood Canyon.

Mark Vessely, M.Sc., PE.

Principal Geotechnical Engineer

Mark Vessely has over 25 years of experience in geologic hazard and risk assessment, emergency response to slope and other ground movements, and design for bridge foundations, retaining walls, pavements, and slope stabilization projects.