Arizona DOT Resilience Pilot Program

The Arizona Department of Transportation (ADOT) is pursuing a “Resilience Pilot Program” (RPP) to improve data and modeling with the aim of reducing incidents of flood, hydraulic-related failure, and extreme weather damage to critical transportation infrastructure. A key element to the new RPP is a partnership with the U.S. Geological Survey (USGS). Leveraging USGS’s resources, the RPP is currently testing new technology such as fixed-wing drone, quad-copter hovercraft and ground based LiDAR imaging to better assess the siting, design, and construction of ADOT’s assets where they interchange with rivers, stream, creeks and floodplains. The modeling focuses primarily on better assessing current weather related risks, but ADOT has begun the process of incorporating climate projections into their project designs. This climate data would be pulled from an earlier pilot project funded by the Federal Highway Administration to assess the climate vulnerability of state-owned transportation infrastructure.

ADOT oversees 30,000 maintenance lane miles and 4,700 bridges statewide. ADOT’s assets face a diverse set of risks including extreme heat, dust storms, wildfire, flooding, landslides, and slope failure. RPP primarily addresses risks related to flooding, especially flash flooding, which is a common problem in the state. Flash floods create dangerous conditions when high volumes of sediment and water flow in a short period of time onto roadways and bridges, causing damage or making them unpassable. These road disruptions are especially problematic in Arizona because the state has many remote populations that risk being cut off from critical services such as hospitals following an extreme weather event.

RPP aims to foster a stronger relationship between ADOT and USGS’s Arizona Water Science Center, allowing ADOT to draw on USGS resources and USGS to practically apply their modeling and research. In mid-2014 ADOT and USGS realized that they had the mutual interested in better understanding flooding, sediment transfers, and the risks to bridges, roads, and drains throughout the state. Based on this combined interest, ADOT petitioned the Federal Highway Administration Arizona Division Office and ADOT’s State Engineer’s Office to support the partnership and use of “next generation” technology, specifically enhanced imaging and 3-D modeling, to measurably upgrade the use of best-in-class science at the Agency. In 2015 ADOT received a $125,000 funding award from FHWA. USGS provided matching funding.  

RPP began with analysis of existing projects, so that the team could understand how utilizing technology such as LiDAR imaging and drones compared to traditional best-estimate field data gathering efforts. ADOT found that the new technology was as good, or better than, human analysis. More importantly, the efforts confirmed that digital imagery gathered down to the 5 centimeter in 2-D and 3-D considerably upgraded risk assessment capabilities. Based on this, ADOT and USGS are analyzing how they can adapt these initial efforts into a more systematic digital approach, make the process more efficient (e.g. by bundling projects by watershed or transit corridor), and minimize any inconsistencies.

Overall, RPP seeks to give ADOT tools to inform environmental planning, better manage storm runoff, improve drainage, and evaluate the potential for structural risks. RPP will use the new imaging and data inputs from drones to limit uncertainties and allow for more evidence based decision making during the planning, design and delivery of transportation projects. For example, this new technology may allow engineers to better assess the potential for scour, which is the removal of sediment such as sand and rocks from around a bridge or other structure, compromising the integrity of that structure. Scour potential is determined by a number of hydrologic variables including water velocity and volume. If this imaging can improve scour assessments, ADOT will be better able to take countermeasures to prevent structural damage. Overall, ADOT sees the potential for digital modeling to improve their understanding of what is happening upstream of a project, and how that project will influence the land and infrastructure downstream. This will provide a much more complete picture of the potential risks.

The process for assessing this new technology is not without challenges. ADOT and USGS were delayed in the fall of 2015 because of the absence of weather events. USGS is better able to do the analysis if they can create images during a storm event or shortly afterwards. Additionally, ADOT must make the case for why this supplementary analysis is needed on top of the current engineering and hydrological assessments that are required. Without this buy-in, project managers, engineers, and other key stakeholders are unlikely to use these models for decisionmaking.

Going forward, ADOT has a number of additional ideas about how they want to utilize these new technologies. One of the ideas is to better incorporate future climate projections. Prior to RPP, ADOT was selected to participate in FHWA Climate Change Resilience Pilot Program to assess extreme weather risks and vulnerabilities in the corridor connecting Nogales, Tucson, Phoenix, and Flagstaff. ADOT used the funding to gather climate data and downscale projections to show climate changes at a 12 kilometer scale. Working with Cambridge Systematics, ADOT developed a batch-processing technique to make the downscaling process more efficient. RPP hopes to use this data layer to better understand the climate risks to priority structures in 2050 and 2100 and to incorporate these risk factors into the decision models.


This Adaptation Clearinghouse entry was prepared with support from the Federal Highway Administration. This entry was last updated on January 28, 2016.


Publication Date: August 2015

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