Synthesis of State DOT and MPO Planning and Analysis on Strategies to Reduce Greenhouse Gas Emissions

Focus Area

Climate Change


Air Quality, Environmental Process






1-2 years

Research Idea Scope

There are several completed and ongoing research efforts that have analyzed the potential of various strategies to reduce greenhouse gas (GHG) emissions in the transportation sector.  Some have taken a scenario approach by looking at the potential from not just individual strategies but bundles of strategies that could be used by state departments of transportation (DOTs) and metropolitan planning organizations (MPOs). These studies have provided a wealth of information to transportation professionals who are or may be asked in the future to reduce emissions from the transportation sector. Despite the progress that has been made, more information is needed on what the real reduction potentials are at the local level. Anticipating that federal policy discussions will continue to consider a national GHG reduction target and/or the inclusion of GHGs in transportation planning, AASHTO and AMPO wish to have more information about what state DOTs and MPOs are doing to analyze and plan the potential GHG reductions from strategies that are realistic to their locale. 
The President and several legislative proposals have suggested a national GHG reduction target of 80% below 2005 levels by 2050. In addition, many states have set or are considering setting GHG reduction targets at similar levels.  Although different sectors of the economy may be asked to achieve different levels of reductions, the transportation sector needs to be prepared to make reductions. Specifically, state DOTs and MPOs need to be prepared to identify strategies and combinations of strategies that would achieve various levels of emissions reductions.  Only a handful of state DOTs and MPOs have attempted to identify and analyze the reduction potential of strategies for their specific area, and it is important for these to serve as a learning opportunity for the rest of the country.
Research Objectives
The purpose of this research is to (1) identify which state DOTs and MPOs have conducted thorough analyses of strategies needed to reduce GHG emissions to a given target level and considered incorporating these strategies into their transportation planning and (2) provide a synthesis of the types of analyses used by each of these state DOTs and MPOs, including similarities and differences between the types.

  1. Determine which state DOTs and MPOs are taking action to reduce GHGs, or analyzing the potential of strategies and combinations of strategies to meet future GHG reduction targets. This list could include, but should not be limited to: Washington State DOT, Puget Sound (PSRC), Washington D.C. (MWCOG), Chicago (CMAP), Los Angeles (SCAG), San Francisco (MTC), San Diego (SANDAG), and Sacramento (SACOG). 
  2. Synthesize what each of the identified state DOTs and MPOs are doing to address GHGs. Look at their policies, analyses, strategies, etc. What are the policies that are driving the state DOT or MPO to take action? What kinds of policies/plans are they implementing? What types of analyses have they done? What strategies are they focusing on and what levels of GHG reductions do they hope to achieve with those strategies? What coordination/outreach processes are they using or planning to use (especially MPO coordination with state DOTs)?
  3. Compare and contrast the analysis methods being used by each state DOT and MPO. What kinds of assumptions are included? What are the limitations? The comparison should provide a discussion of the conclusions drawn by the transportation practitioners from each analysis, and a review of the availability of models and data (and any identified gaps or needs). 
  4. Provide a detailed report based upon Tasks 1 – 3 that summarizes the analyses, policies, and strategies being considered by the identified state DOTs and MPOs. The report shall be prepared to be useful to AASHTO and AMPO leadership, state DOTs, MPOs, and policy makers engaged in Federal and state legislative and policy discussions.
  5. Develop an educational webinar so that other state DOTs and MPOs can learn what the select state DOTs and MPOs identified in the study are doing to address GHG reduction targets.
Relevant Literature

  • Meeting Transportation Greenhouse Gas Reduction Goals in the National Capital Region: A “What Would it Take” Scenario; Transportation Research Board 90th Annual Meeting, 2011, 17p
  • Towards a Better State Climate Action Plan: A Review and Assessment of Proposed Transportation Strategies; Transportation Research Board 90th Annual Meeting, 2011, 14p
  • Cost-Effective Approaches to Reduce Greenhouse Gas Emissions through Public Transportation in Los Angeles; Transportation Research Board 90th Annual Meeting, 2011, 19p
  • The Role of VMT Reduction in Meeting Climate Change Policy Goals; Transportation Research Part A: Policy and Practice, Volume 44, Issue 8, 2010, pp 565-574
  • Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 1: Synthesis Report and Volume 2: Technical Report; U.S. Department of Transportation, 2010, 605p
  • Assessing Mechanisms for Integrating Transportation-Related Greenhouse Gas Reduction Objectives into Transportation Decision Making; NCHRP Web Document, Issue 152, 2010, 100p
  • Achieving California’s Land Use and Transportation Greenhouse Gas Emission Targets Under AB 32: An Exploration of Potential Policy Processes and Mechanisms; University of California, Davis. Institute of Transportation Studies. Research report, 2009, 95p
  • Update the 2003 Report Reducing Greenhouse Gas Emissions from U.S. Transportation; Transportation Research Board, $200000.00, 2009, Active
  • Transportation, Land Use and Greenhouse Gases: A Bay Area Resource Guide; Metropolitan Transportation Commission, 2009, 112p
  • Reducing Greenhouse Gas Emissions for Climate Stabilization: Framing Regional Options; ENVIRONMENTAL SCIENCE & TECHNOLOGY, Volume 43, Issue 6, 2009, 1696-1703
  • Incorporating Greenhouse Gas Emissions Into the Collaborative Decision-Making Process; Transportation Research Board, $800000.00, 2009, Active
  • CO(2) Reduction through Better Urban Design: Portland’s Story; In: Reducing Climate Impacts in the Transportation Sector, Springer Science & Business Media, 2009, pp 139-157
  • State Approaches to Reducing Transportation Sector Greenhouse Gas Emissions; 2009 Transportation, Land Use, Planning, and Air Quality Conference, 2009, pp 95-109

Urgency and Payoff

Suggested By

Paula Hammond, Secretary of Washington State DOT & Chair of AASHTO Climate Change Steering Committee DeLania Hardy, Executive Director of AMPO