Caltrans - Addressing Climate Change Adaptation in Regional Transportation Plans: A Guide for California MPOs and RTPAs

This guide is intended to be a resource to support metropolitan planning organizations (MPOs) and regional transportation planning agencies (RTPAs) in incorporating climate change impacts into their decision-making and planning processes. The guide helps MPOs and RTPAs with assessing risks to transportation assets from different climate stressors, inventorying assets, assessing the vulnerability of assets, and incorporating climate change into long-range planning and investment decisions. To facilitate these processes, the guide includes: background information on climate adaptation, recommended data and information to assist in incorporating climate considerations into regional planning, and a step-by-step process for integrating climate risks into plans.

The guide also accommodates MPOs with varying capacities: “Basic User” MPOs that are conducting climate impact or vulnerability assessments for the first time and have limited resources; and “Advanced User” MPOs that have experience conducting climate impact assessments, greater resources, and strong interagency partnerships. 

Although the Caltrans Guide is geared specifically toward California MPOs and RTPAs, the two approaches could be modified for use by MPOs and RTPAs for long term transportation planning in any state. 

Part I presents background information for both Basic and Advanced Users. This section provides a “101” synopsis of climate science and modeling, discusses the importance of incorporating climate change into regional transportation planning, and describes the sources of current data and climate information available in statewide guidance documents (e.g., the Cal-Adapt web portal and the California Adaptation Planning Guide). It further discusses at a general level the types of transportation infrastructure (e.g., highways, roads, bridges, rail) that may be affected by climate change impacts under a range of scenarios. For each impact (e.g. coastal erosion, flooding), the guide discusses planning, design and operations/maintenance strategies for adapting to the impact.

Part II presents a basic approach for MPOs and RTPAs to incorporate climate adaptation into regional transportation planning, and is designed to accommodate Basic Users with limited time and resources. It divides California’s MPOs and RTPAs into regional groupings and identifies the key climate threats to each region. It presents data from the California Adaptation Planning Guide, and suggests how MPOs or RTPAs can use that data to understand potential climate impacts specific to their regions. 

This section also suggests three steps that MPOs could use to conduct a basic evaluation of their risks and potential responses: (1) assess potential climate effects in the MPO’s region; (2) consider the impacts of climate change on the MPO’s five key transportation assets; and (3) develop a short list of adaptation strategies. The section additionally provides examples of California MPOs and RTPAs that have considered climate impacts in their plans, as well as examples of adaptation projects that have already taken place. Most of the MPOs discussed only include a “brief and high-level” discussion of impacts; however, the guide also includes several MPOs that took a more in-depth assessment (e.g., Monterey, Fresno). Finally, this section includes recommended language that MPOs and RTPAs can incorporate into their plans. 

Part III presents an approach for Advanced Users to fully integrate climate adaptation planning into their regional transportation plans. This section suggests a detailed methodology for incorporating climate impacts, giving a step-by-step process incorporated into five planning modules:

  • Setting the mission, goals, and objectives.
  • Assembling an asset inventory and screening for criticality; selecting and applying climate information. 
  • Evaluating the vulnerability of and risks to key assets. 
  • Prioritizing key assets and developing adaptation strategies.
  • Assessing the plan through monitoring and re-evaluation every four to five years. 


This Adaptation Clearinghouse entry was prepared with support from the Federal Highway Administration. This entry was last updated on December 23, 2014.


Publication Date: February 2013

Related Organizations:

  • California Department of Transportation (Caltrans)


Resource Category:

Resource Types:

  • Planning guides

States Affected:


Go To Resource