Development of the Boston Region MPO’s Disparate Impact and Disproportionate Burden Policy

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What is a DI/DB policy?

The Disparate Impact and Disproportionate Burden (DI/DB) policy (PDF) (HTML) tests when the group of transportation projects funded in the MPO's Long-Range Transportation Plan (LRTP) would unfairly affect minority and low-income people. The MPO board approved the DI/DB policy in November 2020. MPO staff will use the DI/DB Policy to evaluate the likely impacts of transportation projects that change the capacity of the transportation network (for example, building a new train line or removing travel lanes on a road). The analysis will look at two sets of projects:

  • MPO Regional Target-funded projects; and
  • both MPO Regional Target-funded projects and the Massachusetts Department of Transportation-funded regionally significant projects.

Current Updates

The MPO endorsed the DI/DB Policy for use in future LRTPs on November 5, 2020. The endorsement wraps up a two-and-a-half year process to develop the MPO’s first DI/DB policy. Staff also completed a study called Disparate Impact Metrics Analysis (PDF) (HTML) in October 2020, to support the development of the final DI/DB Policy. To review the development of the DI/DB Policy, see the timeline on this page.

Why does the MPO have a DI/DB Policy?

As a recipient of federal funding, the MPO must identify and address potential disproportionately high and adverse effects of its transportation investments on minority populations and low-income populations compared to nonminority populations and non-low-income populations, respectively. Adverse effects can be either a denial or a delay of benefits, or the imposition of excessive burdens. These effects are called disparate impacts when they affect minority populations and disproportionate burdens when they affect low-income populations. The MPO’s DI/DB Policy identifies when transportation projects funded in the LRTP would likely produce DI/DBs. The DI/DB analysis is conducted on the projected impacts of these projects, when all of the projects in the LRTP are finished.

How Did Public Input Shape the DI/DB Policy?

Through a public outreach process, MPO staff

  • collaborated with stakeholders who work with and represent the interests of minority or low-income populations, including
    • Three MPO members representing Everett, Boston, and Arlington
    • Massachusetts Department of Transportation
    • Conservation Law Foundation
    • Transit Matters
    • Mattapan Food and Fitness Coalition
    • Greater Four Corners Action Coalition
    • Transportation, Resources, Information, Planning, and Partnership for Seniors (or TRIPPS)
    • Hessco Elder Services
    • MBTA Rider Oversight Committee
    • Regional Transportation Advisory Council
  • identified which transportation impacts are the most important to address, whether through the DI/DB Policy or through other MPO activities.

To reach these two goals, MPO staff hosted several events that were open to the public (see timeline). The feedback received at these events was used to develop the DI/DB Policy. The policy reflects this input in several ways:

  • The working group’s recommendations are reflected in the final DI/DB Policy. The policy evaluates impacts for three conditions; if all are present, there would be a disparate impact or disproportionate burden:
    1. Whether an impact would be likely;
    2. Whether it would be practically significant; and
    3. Whether it would disproportionately affect the minority population more than the nonminority population, or the low-income population more than the non-low-income population.
  • The metrics that the MPO analyzes for DI/DBs have been updated based on input received from members of the Working Group and participants in the public workshop.

To review the feedback that MPO staff gathered, view the meeting summaries provided in the timeline.


Betsy Harvey, MPO Staff