The National Academies

NCHRP 19-22 [Active]

Equity Impacts of Transportation Revenue Mechanisms and Changing Trends

  Project Data
Funds: $450,000
Staff Responsibility: Camille Crichton-Sumners
Research Agency: Texas A&M Transportation Institute
Principal Investigator: Brianne Glover, JD
Effective Date: 5/10/2024
Completion Date: 5/9/2026
Comments: Research is progress.


This research topic relates to the strategic goals of the Transportation Research Board (TRB) and the American Association of State Highway Transportation Officials (AASHTO) to advance equity in transportation. This topic is also of interest to state departments of transportation (DOTs) that depend on fuel tax revenues to allocate resources. The current fuel tax mechanism for funding surface transportation will likely remain in place for the foreseeable future, despite some advancements made in the future implementation of a mileage-based fee or other revenue options. The federal fuel tax, a fixed per-gallon fee, represents a proportionally higher burden on lower-income families. This disparity may widen as the vehicle fleet becomes increasingly fuel-efficient and alternative fuel vehicle ownership increases. Improvements in vehicle fuel efficiency are developing at a rapid pace. Auto manufacturers are expanding the production of more fuel-efficient vehicles and alternative fuel vehicles, and states have set ambitious goals for new electric vehicle ownership and reduction in greenhouse gas emissions. Meanwhile, lower-income drivers tend to replace their vehicles less frequently and continue to drive less fuel-efficient vehicles. The equity disparity around what proportion of an individual’s income contributes to fuel costs will continue to grow under the current fuel tax structure. Transportation revenues are likely to change with technological advancement, infrastructure demands, and climate change, which will have equity impacts. 


The objective of this research is to develop a tool kit that informs state departments of transportation about equity impacts resulting from alternative revenue structures and includes strategies to mitigate inequities resulting from transportation revenue mechanisms and changing trends. 


The research plan should: 

  • Include a kick-off teleconference with the research team and NCHRP convened within 1 month of the contract’s execution;
  • Address how the proposer intends to satisfy the project objective;
  • Be divided logically into detailed phases/tasks necessary to fulfill the research objective and include appropriate milestones and interim deliverables;
  • Include one face-to-face meeting to review an interim report and a web-conference meeting (NCHRP will provide teleconference services); and
  • Include opportunities for the project panel to review, comment on, and approve milestone deliverables. 

At a minimum, the research plan should include the following activities:

  • Conduct a literature review related to the equity impacts of transportation revenue mechanisms and changing trends;
  • Summarize the state of practice of equity impact analyses related to the implementation of transportation revenue mechanisms at the state and local agency levels and identify the key issues and successful practices related to mitigating consequential inequities;
  • Prepare a technical report that documents the literature review and state of practice summary (include a detailed work plan for the proposed remaining tasks); 
  • Define the user equity impacts that result from changes in trends given the current fuel tax structure;
  • Determine equity impacts from changes in transportation-related revenue mechanisms; and
  • Provide strategies to mitigate inequities.

Prepare final deliverables, which should include: 

  • A conduct of research report documenting the entire research effort. A literature review summary and list of tools that identify equity impacts and other practitioner-ready resources should be included in an Appendix; 
  • A tool kit focused on state DOTs to help them understand and mitigate inequities resulting from transportation revenue mechanisms and changing trends. The tool kit shall include, at a minimum, the following:
    1. Educational materials suitable for a broad range of stakeholders;
    2. A practitioner-ready equity impact matrix and other tools, with graphical output and embedded instructions, to aid state DOTs;
    3. A user’s guide for practitioners; and
    4. Examples demonstrating the use of the practitioner’s tools.
  • A logo-free PowerPoint presentation describing the background, objective, approach, findings, and conclusions;
  • A presentation of findings at two AASHTO committee meetings; 
  • A stand-alone technical memorandum titled “Implementation of Research Findings and Products” (see Special Note I for additional information); and
  • A draft article suitable for publication in TR News (information regarding TR News publication may be found on the TRB webpage http://onlinepubs.trb.org/onlinepubs/trnews/info4contributors.pdf). 


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