Preliminary Study of Climate Adaptation for the Statewide Transportation System in Arizona

The Arizona Department of Transportation’s (ADOT) Preliminary Study of Climate Adaptation for the Statewide Transportation System in Arizona is intended to provide a preliminary assessment of climate impacts on ADOT infrastructure and a framework for how ADOT can begin to incorporate adaptation into transportation decision-making. The study methodology included mapping ADOT decision-makers; completing a literature review of climate science for the region and adaptation best practices for the Southwest; and conducting online and focus group surveys. The study resulted in a map of ADOT decision-makers, a list of climate impacts to transportation assets anticipated for Arizona, and a research agenda with research priorities.

Through a literature review, the study identified projected impacts for the region and developed a matrix of best practices for responding to key risks for transportation assets in the region. The study relied on information from the U.S. Global Change Research Program, Federal Highway Administration (FHWA), and others. Identified climate impacts in the Southwest region include heat waves, early snowmelt, flash flooding, drought, urban heat island effects, degraded air quality, wildfires, and effects on ecosystems and wildlife habitats.

ADOT used information from FHWA to gauge the effect of those impacts on Arizona’s transportation infrastructure. Increased temperatures and heat waves are anticipated to cause thermal expansion of bridges. The study includes a matrix (at pages 16-17) with projected climate impacts for the transportation system and operational responses and design strategies for adapting to those impacts. For example, in response to heat impacts to roads and bridges design strategies include: development of heat resistant paving, heat tolerant landscaping, and rut-resistant asphalt.  In response to increased precipitation, identified best practices include:  protection of critical evacuation routes, upgrading road drainage systems, increasing culvert capacity, seeking alternative routes, improving flood protection, developing a risk assessment for new roads, and using sensors for monitoring water flows.  

The study also identified key stakeholders within ADOT, partner departments and other Arizona entities who would need to be involved in adaptation efforts or who could support ADOT’s adaptation efforts. The study includes a organizational chart of the relevant ADOT decision-makers (by management, technical, and cross-cutting functions) and a matrix of which ADOT departments would need to be involved in implementing a range of responses (at pages 19-24). The study also identifies other Arizona-specific adaptation efforts that could be leveraged to support ADOT’s efforts including Arizona State University’s Decision Theater, the Southwest Climate Change Network, and the Climate Assessment for the Southwest (CLIMAS). The focus group identified other possible partners including the Maricopa and Pima Association of Governments, the ASU Sustainability Program, and the Arizona Department of Environmental Quality.   

The study also included an online survey of ADOT employees and focus group discussions. The purpose of this component of the research was to identify key ADOT staff with decision-making authority, gauge staff perceptions, identify ADOT guidelines and specifications relevant to climate impacts, map out relationships between departments, and brainstorm potential tools, data, guidance and other resources needed by ADOT staff for integrating climate change adaptation into decision-making.  Results of the online survey and the focus groups revealed several key pieces of information:

  • A majority of ADOT staff (56%) believe that climate change is already affecting ADOT operations and identified heat, flash flooding, dust storms, and wildfires as impacts of primary concern.
  • ADOT employees are using different time horizons to make decisions in the course of their work.
  • Employees see most of the identified climate impacts as relevant to their job functions.
  • Respondents had varied responses to questions about specific climate effects and the tools, data, and guidance needed to address them, and suggestions for areas for future research.

The focus group identified ADOT efforts that could be leveraged to support adaptation including Arizona’s Disaster Recovery Framework, ADOT’s Feature Inventory System, ADOT’s Maintenance Service Leadership Team, efforts to separate budgets for maintenance versus emergency response, correlating extreme weather trends with maintenance budgets, and GIS and spatial mapping capabilities. The group also identified past successful models where ADOT coordinated across departments and between agencies which included: Best Management Practices for Storm Water Management; Building a Quality Arizona (a long-range cross-disciplinary plan about state infrastructure needs); Wildlife Cross and Connectivity Projects; and LEED Green Design.  

Research needs identified by the focus group included to: update floodplain maps with current data on drainage; link climatological events with economic impacts; create protocols for dealing with specific climate events; talk about climate change across disciplines; develop a policy for erosion and roadside vegetation; develop scenarios for adaptation; develop agency-wide or project-specific performance measures; generate reliable data on rainfall and temperature projections; link adaptation to NEPA review process; involve budget analyst in discussion of adaptation options; among others.

The final part of the report sets a future research agenda for ADOT; recommendations include:

  • Develop an overall framework for climate adaptation for ADOT and integrate it into decision-making in design, operations and other areas. This framework should assess risks and vulnerabilities, help ADOT select adaptation options, and include a component for monitoring and evaluating outcomes.
  • Establish an engaged project team within ADOT to coordinate climate efforts and advance recommendations throughout the agency.
  • Conduct an environmental audit of ADOT business practices and activities aligned with climate adaptation planning, creating a forum where staff could share ideas and projects across the Department.
  • Seek new opportunities for funding, from the federal government and other sources.
  • Identify practices within the planning, design, and operations divisions that are low cost and highly effective for climate purposes.
  • Pursue an FHWA climate adaptation pilot, to fund a small project within ADOT.

The report concludes by focusing on three specific areas of research. First, ADOT staff need a clearer understanding of how they could better integrate climate impacts into current guidelines and specifications. Second, ADOT staff members need to better coordinate and be more active in adapting for a changing climate. And third, ADOT employees need better data to assess the impacts of climate change in Arizona in order to plan for the future.

The report was prepared by Cambridge Systematics, Inc. The study was funded in part by a grant from the Federal Highway Administration and by ADOT.

Since the development of this report, ADOT has been involved in several additional research efforts to support better information and decision-making surrounding climate change and transportation infrastructure. ADOT participated in FHWA’s second round of Climate Change Adaptation Pilot Projects between 2013 and 2015, studying vulnerabilities related to heat, drought, and intense storms along the corridor connecting Nogales, Tucson, Phoenix, and Flagstaff. Additionally, ADOT has created a partnership with USGS to improve data and modeling that can better assess flood-related risks, and hopes to incorporate climate projections from the FHWA pilot project into this effort in the future. 

This Adaptation Clearinghouse entry was prepared with support from the Federal Highway Administration. This entry was last updated on July 12, 2016.


Publication Date: March 2013

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