2010 California Regional Transportation Plan Guidelines - Recommendations for Adapting the Regional Transportation System to Climate Change

The California Regional Transportation Plan (RTP) Guidelines provides a uniform transportation planning framework for use by Metropolitan Planning Organizations (MPOs) and Regional Transportation Planning Agencies (RTPAs). The Guidelines cover all aspects of regional transportation planning, with one section offering recommendations for considering climate change. The Guidelines recommend that as a best practice, MPOs and RTPAs should begin to incorporate climate change into their long-range transportation plans.

The Guidelines present a comprehensive framework for MPOs and RTPAs to follow in developing RTPs, and list three tiers of guidelines: binding federal and state statutory or regulatory “requirements” (shall), permissive or optional federal and state “recommendations” (should), and discussions of “best practices.”

The Guidelines recommend that as a best practice MPOs and RTPAs “should begin to address climate change in their long range transportation plans,” notwithstanding a lack of information about future climate impacts. The guide identifies several ways that MPOs and RTPAs can start to prepare for the impacts of climate change on infrastructure, such as developing preliminary maps of vulnerable infrastructure that may be affected by precipitation changes, extreme heat, and sea-level rise. The Guidelines also recommend that MPOs and RTPAs re-evaluate design and planning standards to account for climate change, to ensure that new infrastructure is designed and built to be resilient to future impacts.

As a state law requirement, the Guidelines outline compliance with the California Environmental Quality Act (CEQA) which requires California agencies to consider and inform the public of the environmental impacts of their actions, similar to the National Environmental Policy Act (NEPA). CEQA applies to Regional Transportation Plans and the projects listed in it unless the project is statutorily or categorically exempt. Although RTP Guidelines do not specify the climate adaptation-related requirements of CEQA, the California Governor’s Office of Planning & Research has interpreted CEQA to require California agencies to evaluate the impacts of developing state projects in locations vulnerable to hazardous conditions and to consider whether such hazards may be exacerbated by climate change.

The Guidelines acknowledge that several studies project impacts and high economic costs from a variety of climate change effects: increased temperatures, snowpack melt, precipitation changes, increased wildfire severity, sea-level rise, extreme weather, and other impacts on biodiversity and habitats. These climate change effects may have substantial impacts on the transportation system, such as: flooding of coastal airports, highways, and roads; disruption of rail lines by landslides; buckling of roadways caused by heat waves; and mudslides caused by fire-damaged watersheds. These impacts will vary regionally and locally, and the degree of risk to transportation infrastructure will depend on the location, types, and functions of the transportation assets.

The Guidelines also summarize the background of California’s statewide adaptation effort, beginning with Governor Schwarzenegger’s Executive Order S-13-08 directing the California Natural Resources Agency to develop the California Climate Adaptation Strategy (CAS). The CAS includes adaptation strategies for California’s transportation infrastructure, focusing on state-level efforts. The Guidelines suggest that MPOs and RTPAs also incorporate the practices recommended in the CAS to the extent they are feasible at the regional level.

As of July 2016, the California Transportation Commission is in the process of updating the Regional Transportation Plan Guidelines, and anticipates completing this process and releasing new Guidelines in December 2016.


This Adaptation Clearinghouse entry was prepared with support from the Federal Highway Administration. This entry was last updated on July 6, 2016.


Publication Date: April 7, 2010

Related Organizations:

  • California Transportation Commission


Resource Category:

Resource Types:

  • Agency guidance/policy
  • Planning guides

States Affected:


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