BACKGROUND

For state departments of transportation (DOTs), comparisons of alternative build and no-build scenarios in project-level air quality analyses can affect project selection and approval. These comparisons typically focus on emissions and/or ambient concentrations of specific pollutants, including greenhouse gases, mobile source air toxins, particulate matter, and carbon monoxide. However, the emission and concentration estimates between pollutant classes are not directly comparable and cannot be directly aggregated. As a result, decision-making on National Environmental Policy Act (NEPA) project alternative analyses becomes constrained, limiting the ability to consider potential multi-pollutant air quality impacts, which may differ substantially by alternative.

One possible solution to this problem is to translate the results for each pollutant class into a common risk-based metric that would allow for aggregation and comparison. Potential synergistic effects could also be considered as part of the aggregation. NEPA alternatives could then be compared on the common basis of potential air quality impacts for each alternative in terms of aggregate risk. Research is needed to support the development of a simplified air quality risk assessment methodology that provides state DOTs with increased flexibility and capability to make informed air quality decisions at the project level.

OBJECTIVE

The objective of this project is to develop (1) a guide for applying a simplified air quality risk assessment methodology for project-specific NEPA air quality alternative analyses to be used by state DOTs at their discretion and (2) a compendium of historical and notional case studies illustrating the developed risk assessment approach and its applications, which may be appended to NEPA air studies to add transparency and provide context to stakeholders. 

TASKS

Task 1. Conduct a targeted review of literature, tools, and other relevant resources to determine the state of air quality assessment and alternatives analysis practices. 

Task 2a. Develop a subject-matter expert outreach plan to be implemented in Task 3. The outreach plan should target practitioners and subject-matter experts from state DOTs, state divisions of air quality, and other relevant organizations. 

Task 2b. Develop an initial plan to execute the larger outreach effort described in Task 9. Submit technical memorandum #1, including the results of Task 1 and the plans developed in Tasks 2a and 2b. NCHRP approval of technical memorandum #1 is required before work on subsequent tasks may begin.

Task 3. Administer and summarize the subject-matter expert outreach from Task 2a. Submit technical memorandum #2, including a summary of the outreach. NCHRP approval of technical memorandum #2 is required before work on subsequent tasks may begin.

Task 4. Examine relevant analysis tools and methodologies, focusing on the capabilities and limitations of available resources to meet future user needs.

Task 5. Propose a method to achieve the project objective to be fully developed in Phase II. At minimum, the method should include the following:

• Proposals for the modeling of relevant transportation projects, including methods to complement existing on-road transportation air quality models and tools and to distinguish impacts from on-road emissions sources from other sources. The number and variety of these projects are at the discretion of the proposer.
• Reviews of air quality risk assessments conducted for NEPA to date, accounting for each relevant pollutant. 
• Consideration of project-level, transportation-related air quality impacts on public health, especially regarding affected and vulnerable communities and the features of those communities, including the presence of schools, poverty level, geography, climate zone, flood susceptibility, and other factors.
• An annotated outline of a guide to further advance the state of the practice.
• An annotated outline of a case study compendium as well as proposed historical and notional transportation use cases. The compendium should include an executive summary (or separate template text) designed for inclusion in the main NEPA air quality report that references the appendix/compendium for additional detail.
• A mock-up of a supplementary template for the future use of state DOTs in support of their air quality practices. The template should include a disclaimer acknowledging the uncertainty present in air quality modeling and the assumptions informing the development of the template.

Task 6. Prepare Interim Report No. 1, which documents Tasks 1 through 5 and provides an updated work plan for the remainder of the research. The updated plan must describe the process and rationale for the work proposed for Phase II.

PHASE II: Execute the Method and Produce Final Deliverables

Task 7. Execute the research method according to the approved Interim Report No.1.

Task 8. Develop the guide and case study compendium. The draft guide and case study compendium shall be submitted for NCHRP approval no later than 6 months before the contract end date.

Task 9. Conduct a follow-up stakeholder outreach effort, with the goal of eliciting practitioner and community feedback on the draft deliverables. Summarize the outreach in an online debrief with the NCHRP, including any recommended changes to the deliverables. Any proposed changes must be approved by the NCHRP.

Task 10. Prepare the final deliverables, which shall include the following:

• A conduct of research report documenting the entire research effort;
• The final guide and case study compendium;
• A stand-alone template for use in NEPA documentation prepared by state DOTs;
• Public outreach materials, including a PowerPoint presentation with speaker notes; and
• A stand-alone technical memorandum titled “Implementation of Research Findings and Products”.

STATUS: Proposals have been received in response to the RFP. The project panel will meet to select a contractor to perform the work.