Enhancing Equitable Access: Developing a Methodology to Measure Project-Level Impacts on Destination Accessibility for Priority Populations

Contacto

Sustainable Transportation and Communities Division
Correo electrónico
stcd@arb.ca.gov

Background

California Climate Investments is a statewide initiative that puts billions of Cap‑and‑Trade dollars deposited into the Greenhouse Gas Reduction Fund (GGRF) to work towards reducing greenhouse gas (GHG) emissions, strengthening the economy, improving public health and the environment. 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. Quantification methods are designed to estimate the GHG benefits and co-benefits from funded projects.

The goal of this contract is to develop a methodology for assessing the project-level impacts of California Climate Investments (CCI) transportation and housing projects on access to key destinations. Specifically, the contract will focus on measuring changes in destination accessibility for California communities, including an emphasis on priority populations, resulting from CCI-funded transportation and housing projects.

This contract aims to provide a deeper understanding of benefits from transportation and housing investments, beyond simply identifying the amount of funding allocated to their communities. The methodology developed will help CCI determine which types of transportation projects most effectively and efficiently improve access to key destinations for priority populations.

The ultimate goal is to integrate the destination accessibility metric co-benefit into the application review process for select CCI programs and incorporate key variables used to calculate the metric (e.g., increase in number of jobs or key destinations accessible as a result of a project) as part of the post-selection project benefits reporting process. Variables factored into the metric will be calculated using distinct methods and data sources, while the composite accessibility metric will combine and weight these variables to produce an overall destination accessibility score for use during the application phase. After project selection, the key variables behind the overall score can be reported as standalone values to highlight the specific accessibility benefits of funded CCI projects.

This contract responds to feedback from administering agencies, who have indicated that quantifying the destination accessibility impacts of projects would complement existing greenhouse gas (GHG) reduction metrics. Some agencies have noted that while certain projects may not be highly competitive based on GHG reductions alone, they could significantly improve access to destinations. A standardized, quantitative approach to measuring destination accessibility will help ensure these benefits are systematically accounted for across projects. On the benefits reporting side, the relevant key variables of the methodology which can be reported will help estimate how CCI investments—both individually and cumulatively across programs—enhance access to jobs and key destinations for priority populations statewide.

While several existing methodologies quantify the impact of transportation investments on destination accessibility, most are proprietary and/or require significant technical expertise and processing power. This contract seeks to advance knowledge in this space by developing a more user-friendly methodology that can be easily applied across different CCI programs.

 

Objective

The goal of this contract is to develop a statewide methodology for measuring changes in destination accessibility resulting from transportation, land use and housing investments in California, with a specific focus on benefits for priority populations. This methodology will assess how project improvements enhance access to key destinations, considering both increased access to opportunities (e.g., job centers, essential services, education facilities) and trip characteristics that improve travel ease (e.g., open-loop payment systems, reduced transfers, fare integration).

The methodology should primarily be applicable in the project selection process. Additionally, some of the key variables used to calculate the metric may be used to report on destination accessibility impacts of funded projects. For applications, the objective is to integrate a destination accessibility metric into the scoring criteria for various CCI transportation programs (e.g., AHSC, STEP, TIRCP, LCTOP, CMO). For co-benefits assessment, the goal is to quantify additional project benefits, such as increased job accessibility and improved connectivity to key destinations for priority populations as feasible based on the key variables available via the calculation of the overall destination accessibility metric. The methodology should be at the geographic granularity of at least census tracts (if not block groups).

To ensure broad applicability across transportation programs, the contract will analyze destination accessibility benefits from a variety of transportation investments, including:

  • Bike and pedestrian infrastructure
  • Transit vans and shuttles
  • Microtransit
  • Fixed-route transit (e.g., light rail, heavy rail, bus rapid transit, urban bus, ferry)
  • Housing investments

This approach will help ensure that transportation investments effectively improve access to key destinations, particularly for priority populations.

 

Scope of Work

Task 1: Review of literature and existing access to destination methodologies.

Develop a literature review of destination accessibility metrics, with attention to the range of methodologies used to measure destination accessibility. Some methodologies report multiple metrics—such as the average number of grocery stores, jobs, schools, and parks reachable within a given travel time by different modes (car, transit, walking, biking). Since our analysis will require combining these into a composite score to assess overall project impact, the review should examine how different studies approach this issue. Be sure to explore which individual metrics are commonly included in composite calculations and how they are weighted or integrated.

Several CARB contracts have conducted literature reviews on related topics. This task will begin by reviewing those materials for relevant publications, including:

There are also several relevant contracts underway that will be shared with researchers as available for inclusion in the literature review. The literature review should also incorporate recent research on the topic.

Additionally, this task should compare methodologies used by other state and federal agencies (e.g., Caltrans) to measure access to destinations, ensuring that the metrics and methods proposed in Tasks 2 and 3 align as closely as possible, particularly with existing California state-level approaches for project selection. Including:

Interim Deliverable

  • Written literature review narrative, including list of references/resources reviewed.
  • Comparative analysis of existing access to destination methodologies being used by other California state agencies, noting points of alignment and diversion from one another as applicable.

Task 2: Recommend a Metric for Measuring the Impact Transportation Investments have on Access to Destinations

Recommend a destination accessibility metric to measure change in access to key destinations as the result of a transportation investment. Suggestion should include both the individual variables (e.g., additional jobs reachable within 30 minutes by different modes, additional key destinations reachable within 30 minutes by different modes, etc.) and concept for creating a composite destination accessibility score for given geographic locations. The suggestions should also include detailed information on what data points calculating the components of the metric will require. Suggested data the metric calculations rely on must be available publicly statewide or be existing or easily collectable project-level information. The suggested metric calculation should be transparent and flexible enough to allow for future modifications and adjustments as needed by CARB staff after the contract term has concluded.

Metric should be calculatable based on expected changes to the transportation system/network based on the project components compared to a baseline set of assumptions. The suggestion should include specific information about the baseline that will be used to measure the change in each metric component suggested.  There is an ongoing research contract on measuring existing destination accessibility at a granular level, the contractors can work with CARB staff to leverage the findings for this contract, as helpful for calculating the baseline accessibility conditions. 

The metrics should be calculated at the census tract or block group level. The output should also be aggregable to the project level (i.e., sum of project’s impact across the census tract(s) or block group(s) impacted by the project) and broken out by priority population designation (i.e., sum of project’s impact on census tract(s) or block group(s) designated as disadvantaged communities, low-income communities, etc.).

This task should also include an analysis of potential equity implications of the suggested metric components. For example, is there a risk of urban census tracts scoring much higher than rural census tracts on a given metric based on the underlying data inputs the calculation would rely on? Or similarly, is there a risk of geographic areas of the state designated as priority populations scoring higher or lower based on the existing destination accessibility conditions in these locations? Or is there a likelihood of locations that are majority minority scoring higher or lower?

Interim Deliverable

  • Written narrative explaining the rationale for selecting each component of the destination accessibility metric, with references to the literature review and other methodologies reviewed, including approaches to composite scoring. Documentation should be detailed enough that CARB staff could adjust specific components as needed once the contract term has concluded.
  • Suggestion of which variables of the metric calculation could be applicable to co-benefit assessment for selected projects.
  • Suggestion of which variables of the metric calculation could be applicable to co-benefit assessment for selected projects.
  • List of data sources for each variable that is part of the metric, including project-level information needed for calculations. Specify data requirements for both baseline and project impact metric calculations. Analysis of potential equity implications of including and weighting different metrics in a composite score.

 

 

Task 3: Explore Additional Data Inputs Needed to Calculate the Access to Destinations Metric Based on Land Use Changes and Housing Investments

Explore the possibility of calculating the metric suggested in Task 2 to measure change in access to key destinations as the result of housing investments. Make recommendations around the feasibility of calculating the recommended metric based on expected changes to housing density (and thus population density) in a given location compared to a baseline set of assumptions. Including information on the data and/or project information and the computational needs to make such a calculation.  

As with Task 2, provide a section in the written narrative outlining the potential equity impacts of the metric components if they are also applied to housing investments.

Interim Deliverable

  • Written narrative explaining a recommendation of inclusion versus exclusion of housing/land use into the analysis product (Task 4).
    • Must complete this deliverable and agree with contract manager on including or excluding the capability to assess housing projects into the analysis product prior to moving on to Task 4.

 

Task 4: Develop a Destination Accessibility Analysis Product

Create a project-level analysis product to calculate the metric suggested in Task 2 and if deemed feasible, Task 3. The product should be able to estimate the cumulative change in destination accessibility based on inputs specific to a project’s components and its expected changes to the transportation network or residential density/land use in a specific location. As noted in Task 2, the analysis should be done at the granularity of at least census tract (if not block group) but should also be aggregable for the entire project if it impacts multiple tracts or block groups. The results should also be broken out by priority population designation (i.e., the sum impact on access to destinations for all census tracts or block groups designated as low-income and disadvantaged communities and impacted by the project).

Based on the metrics chosen and the data required, the analysis product could be an interactive interface, an excel-based tool, or other interactive application. Based on the metrics chosen and the data required, the analysis product could be an interactive interface or an excel-based document. Attention should be paid to the usability of the product, making it as simple as possible for users. The product must be open source and/or accessible to program applicants, administering agencies, and California Climate Investments staff, as it will be used in project applications and for assessing the benefits of funding projects. Due to potential limitations in processing speed for network-based destination accessibility calculations, contractors can consider using previously modeled outputs from similar changes to estimate results more efficiently.

As part of this task, the contractors should also provide documentation that allows for CARB staff to update the data underlying the analysis product. As part of this task, the contractors should also provide documentation that allows for CARB staff to update and adjust all components of the analysis product (i.e., the underlying data, variables, weighting, etc.)

Interim Deliverable

  • Complete and usable project-level analysis product.
  • Methods/documentation/code for updating the data underlying the analysis product in the future.

 

Task 5: Test Results Using Past Project Information

Utilizing the analysis product, produce test outputs for at a minimum of two previously funded projects from each of the following California Climate Investment programs: AHSC, STEP, TIRCP, LCTOP, and CMO.  Ensure that the projects selected cover all the possible modes included in the analysis methodology.

Interim Deliverable

  • Output data results from the tested projects.

Minimum Expectations and Application Process and Requirements

Information on required material and process during the preproposal phase and expectations on the contract are found on the Solicitation landing page.

Timeline

This project is anticipated to be completed in 18 months from the start date. Cost shall not exceed $500,000.

Scoring Criteria

Responsiveness to the goals and objectives outlined in the pre-proposal solicitation(15 points)

Proposers should demonstrate a clear understanding of the policy objectives and research needs that CARB aims to address with this project while highlighting their expertise on the subject. The pre-proposal should consider various aspects of the need and identify or acknowledge any potential biases. It should outline, in sufficient detail, the proposed approach to meeting the requirements of the Solicitation. The pre-proposal must detail work that aligns with the objectives outlined in the Contract Solicitation:

  • Develop a standardized methodology to measure how CCI-funded transportation and housing projects impact destination accessibility, with a focus on priority populations.
  • Develop a destination accessibility metric and an analysis product for CCI program scoring criteria and benefits assessment to help prioritize projects improving mobility for disadvantaged communities.
  • Collaborate with administering agencies and stakeholders to align with existing state-level methodologies.
  • Ensure the methodology is transparent, accessible, equitable, and practical for program administrators and applicants.

Policy relevance/benefits to the state(10 points)

Does the pre-proposal describe how the project will provide data, information, and/or products to support CARB in achieving its mission?

This project supports CARB’s policies by advancing equitable access to transportation improvements for priority populations. By measuring changes in destination accessibility, the project aligns with CCI’s goal of ensuring that investments benefit these communities, enhancing mobility and access to opportunities. It will contribute to the integration of equity-focused metrics into the project selection and benefit assessment processes, promoting CARB's commitment to reducing disparities and improving environmental justice across California.

Previous work (15 points)

Do the researchers have relevant experience in this area? Is the team composed of a multi-disciplinary team of experts? Do they discuss how they will build on previous relevant work funded by CARB, other state agencies, and any other appropriate organizations (e.g. Caltrans; CalSTA; Strategic Growth Council; other CCI administering agencies)? If community engagement is included, the relevant contractor should describe prior experience in community engagement and provide letters of support, references or a community impact statement detailing how their previous work has benefitted communities. Five points will be reserved for project teams that meet at least one of the following criteria:

  1. The project team is multi-disciplinary.
  2. The project team includes members from various universities, non-academic institutions, or community-based organizations.
  3. The project team includes one or more members who will contribute significantly to the project (e.g., a principal investigator, co-principal investigator, or co-investigator, contributing 25% or more of their time) who have not worked with CARB in the past 5 years.

Technical merit (25 points)

Describe the technical strengths and/or weaknesses of the pre-proposal. Proposers should demonstrate the logic and feasibility of the methodology and technical approach, outline the sequence and relationships of major tasks, and explain how the work will be carried out. The proposal should also explain how the proposed methods are robust and how the results will be validated. Consider how well the draft proposal addresses these areas:

  1. Is the proposed measurement approach appropriate? Are the technologies being considered suitable, and will the proposed analysis yield relevant results?
  2. Does the proposed work address all the deliverables outlined in the “Deliverables” section? If not, the proposal should not be considered for funding.
  3. The review team will select only one pre-proposal for development into a full proposal. If this pre-proposal shows potential, what areas or topics should be prioritized or further explained in the full proposal?

Level and quality of effort to be provided(15 points)

Does the pre-proposal allocate time and resources effectively to ensure the study objectives are met? Is the supervision and oversight sufficient to keep the project on schedule? Is the distribution appropriate for activities such as research, evaluation, analysis, data reduction, computer simulation, report preparation, meetings, and travel?

Cost effectiveness (20 points)

Is the cost appropriate for the proposed work? Does the proposed work appear feasible within the requested budget? Projects that include co-funding should be evaluated more favorably.

Scoring Criteria Scoring Guidance

91-100 points. Exceptionally strong. The submission is technically strong, meets stated research objectives, is cost-effective, and has a high potential to be successfully completed.

81-90 points. Strong. The submission is technically sound.

71-80 points. Mixed. The submission has either strong technical merit or strong policy significance, but not both.

61-70 points. Weak. The submission is not sufficiently linked to the needs of the Board and offers limited technical merit.

60 points or below. Unacceptable. The submission is not linked to the interests or needs of the Board and lacks technical merit.

 

[i]Priority communities encompasses various terms CARB uses, such as priority populations, communities of concern, protected classes, or disadvantaged communities to identify, define, and address the intended populations and communities.

[ii]Priority communities encompasses various terms CARB uses, such as priority populations, communities of concern, protected classes, or disadvantaged communities to identify, define, and address the intended populations and communities.