California Air Resources Board

I.       Objective

The California Air Resources Board (CARB) develops the quantification methodology for estimating greenhouse gas (GHG) reduction benefits from projects proposed for funding by the Strategic Growth Council’s Affordable Housing and Sustainable Communities Program (AHSC). The objective of this research study is to investigate and propose updates to the method CARB’s uses for calculating vehicle miles travelled (VMT) and associated VMT reductions of proposed housing projects including location-specific VMT, proximity to transit, and project density. This study may include identifying alternatives to the assumptions and data currently used in the calculation of VMT estimates and reductions.   

II.      Background

Under California’s Cap-and-Trade program, the State’s portion of the proceeds from Cap-and-Trade auctions is deposited in the Greenhouse Gas Reduction Fund (GGRF). The Legislature and Governor enact budget appropriations from the GGRF for State agencies to invest in projects that help achieve the State’s climate goals. These investments are collectively called California Climate Investments.

Senate Bill (SB) 862 Committee on Budget and Fiscal Review, Chapter 36, Statutes of 2014 requires CARB to develop guidance on reporting and quantification methods for all State agencies that receive appropriations from the GGRF. Guidance includes developing quantification methodologies for estimating GHG emission reductions and other social, economic, and environmental benefits of projects, referred to as “co-benefits.” CARB develops quantification methodologies to provide project-level GHG emission or co-benefit estimates that are supported by empirical literature. This work relies on a review of the available science, coordination with the administering agencies, and outside experts and academic partners to obtain technical assistance and expertise, as needed. 

CARB staff periodically reviews each quantification methodology and benefits calculator tool to evaluate their effectiveness and update methodologies to make them more robust, user-friendly, and appropriate to the projects being quantified. CARB may review and update GHG quantification methodologies and co-benefit assessment methodologies based on: new or evolving project types; new legislation; available resources; new scientific developments or tools, or modifications in the analytical tools or approaches upon which the methodologies were based; or input from administering agencies or the public.

The Affordable Housing and Sustainable Communities program (AHSC) funds affordable housing and transportation projects that reduce vehicle miles traveled (VMT). CARB’s quantification methodology for AHSC, estimates avoided passenger VMT from housing and transportation projects using data and methods from the report called Quantifying Greenhouse Gas Mitigation Measures developed by the California Air Pollution Officers Association (CAPCOA)[1]. CARB adapted some measures in the CAPCOA report methodology to align with the AHSC program’s goals and requirements. CARB staff have identified three additional measures in the current methodology for potential revisions and modifications. This research study will help CARB evaluate, and update if necessary, the assumptions and data to calculate the following:

• Residential VMT estimates: The current methodology is limited in measuring the VMT benefits of housing projects located in location-efficient areas compared to the average project built in less location-efficient areas within a county or region. This research project would identify methods and data to better capture the location-specific VMT estimates and reductions.
• Proximity to Transit: Currently, the AHSC program requires all housing projects seeking funding to be located within a half mile of a transit station or stop. Recent research suggests that the impact of transit proximity on VMT reductions vary even within a half mile of transit stations and stops, suggesting the VMT of a project located zero miles to a station will have different VMT reductions than a project at the half mile mark.[2] This research project would investigate the possibility of implementing a transit proximity factor in the AHSC quantification tool and assess its applicability to the AHSC program’s different Project Area Types.
• Project Density: Currently, project density is calculated as dwelling units per acre to align with the underlying data used to calculate density elasticities from the Transportation Engineers’ Trip Generation Manual. Stakeholders have questioned whether this approach accurately accounts for density of projects with larger units and more bedrooms. This research project would investigate whether using a bedroom count to calculate density is possible and if so, this research will help CARB determine new density baselines for Project Area Types based on a bedrooms per acre calculation.

III.     Scope of Work

Task 1 – Kick-off Meeting

At the beginning of the project, a kick-off meeting will be held with CARB staff, and staff from partner agencies, to discuss the details of the project, including a review of the AHSC Program’s policy goals and the contractor’s proposed timeline for deliverables.

Task 2 – Evaluate existing methodology and identify alternate methods and data

1. The contractors will evaluate the existing method for calculating residential VMT estimates, transit proximity and project density to determine if any revisions are needed.
2. The contractors will then conduct a literature review to evaluate alternate methods and data sources to calculate the identified metrics. Review can include but is not limited to recent transportation-land use studies and technical reports.
3. The contractors will present a synthesis of alternate methods and data sources and work with CARB program staff to identify 2-3 approaches for each identified measure for further analysis.

Task 3 – Sensitivity Analysis

In close coordination with CARB staff, the contractors will test the 2-3 approaches identified in Task 2c to assess any regional differences in data availability and outcomes and identify any unintended consequences to applying the new methods.

Task 4 – Recommendations

Based on the results of the literature review and in consultation with CARB staff, the contractor will develop recommendations for how to update the identified VMT calculations in the AHSC Quantification Methodology and Benefits Calculator Tool. The contractors should make recommendations that are applicable to the AHSC program, keeping in mind program design and requirements. It should also include a discussion for how the recommended changes will advance the AHSC program’s policy goals. The recommendations should include a justification for the proposed change along with the available data source needed to make the change and any data limitations. Additionally, the contractors should outline a step-by-step approach for implementing the proposed change as well as the limiting factors to implementation. Finally, the contractors should also specify the need for any additional user input or conversion factors to implement alternate methods.

Task 5 – Reports

The project will include two reports. An interim report shall be completed soon after the suitability assessment with a summary of high-level results. The interim report will be presented to CARB staff to help guide further data analysis to ensure that the final report include relevant policy recommendations. The final report will document all methodologies, data analysis, and processes employed in the completion of the research and include a plain-language summary of policy recommendations.

Task 6 – Communication

The contractors will schedule virtual informal monthly check in meetings with CARB staff as well as virtual quarterly progress meetings and reports. The contractors will propose a timeline for CARB staff to review written deliverables.

IV.    Deliverables

At Beginning of Contract

• Work with CARB staff at the beginning of the project to create a 1-page plain-language outreach deliverable for the public describing the project’s goals, process, and planned deliverables (available in multiple languages, template will be provided).
• Detailed timeline for CARB staff to review drafts of written deliverables.
• Draft of Literature Review to further refine research goals.

During Active Contract Period

• Quarterly Progress Reports
• Quarterly Progress Meetings
• Informal monthly progress update meetings with CARB contract manager

Prior to Contract Close

• Initial presentation of possible approaches
• Interim report with high-level results
• Draft Final Report
  • Include a plain language summary in draft final report
  • Include an equity implications section in draft final report
  • Peer reviewed publications should be publicly available (please budget for this expense; submission-ready publications shall be reviewed by CARB staff).
• All data, analyses and analytical tools generated through the course of this project
• Final report
• Presentation of summary results

Additional deliverables to be determined in consultation with CARB staff.

V.     Timeline

It is anticipated this project will be completed in 12 months from the start date (sometime between February and June 2023).  The estimated budget for this project is up to $175,000.

VI.    Scoring Criteria

1. Responsiveness to the goals and objectives outlined in the pre-proposal solicitation (25 points)

Proposers should demonstrate a clear understanding of the policy objectives and research needs that CARB seeks to address with this project and should convey their knowledge of the subject. The pre-proposal should explain—in adequate detail and clear, understandable language—how the proposed project satisfies the project objectives: to investigate and propose updates to CARB’s method for calculating VMT reductions of housing projects seeking AHSC funding.

2. Work experience and subject matter expertise (20 points)

The pre-proposal should demonstrate that the proposers have the work experience or subject matter expertise required to successfully carry out the proposed project as described. Additionally, the pre-proposal should describe how the project will build upon previous relevant work that was funded by CARB, other regional, state, and federal agencies. The proposers should understand the land use impacts to travel behavior and the common barriers to quantifying the VMT reductions from land use measures.

3. Expanding expertise (10 points)

The pre-proposal should explain how the project team expands expertise such as by incorporating multidisciplinary expertise or perspectives, including members come from various public universities, non-academic institutions, or community-based organizations, or providing opportunities to build skills and expertise for individuals from underrepresented groups. Reviewers will consider if key personnel contributing significantly to the project (i.e., a principal investigator, co-principal investigator or co-investigator, contributing 25 percent or more of their time to the project) have not worked with CARB in the past five years.

4. Explanation of technical or methodological approach (25 points)

The pre-proposal should clearly explain the logic and feasibility of the methodology and technical approach to the project, spell out the sequence and relationships of major tasks, and explain methods for performing the work. The pre-proposal should include a clear description and plan for how each task will be completed. The proposer should specify why the methodology proposed is the best method to reach the desired populations.

5. Level and quality of effort and cost effectiveness (20 points)

The pre-proposal should describe how time and resources will be allocated and demonstrate how this allocation ensures the project’s success. Pre-proposal reviewers will evaluate, for example: if the objectives of the project can be met given this allocation, if there is adequate supervision and oversight to ensure that the project will remain on schedule, if time and cost are appropriately divvied up across different project tasks and stages.

[1]CAPCOA’s report is at http://www.capcoa.org/wp-content/uploads/2010/11/CAPCOA-Quantification-Report-9-14-Final.pdf.

[2]Boarnet, M. G., Bostic, R. W., Rodnyansky, S., Burinskiy, E., Eisenlohr, A., Jamme, H. T., & Santiago-Bartolomei, R. (2020). Do high income households reduce driving more when living near rail transit?. Transportation research part D: transport and environment, 80, 102244.