Boston REGION MPO major Infrastructure Definition



The definition of a major infrastructure (MI) project as identified in the Boston Region MPO’s Long-Range Transportation Plan (LRTP), Destination 2040, adopted in August 2019, is a project that changes capacity to the transportation network and/or costs more than $20 million.


In November 2019, the MPO discussed whether the current definition should continue to include the $20 million threshold, and at that meeting voted to do so. This issue arose again in spring 2020 during discussions about a federal fiscal years (FFYs) 2020–24 Transportation Improvement Program (TIP) Amendment when cost increases caused three Complete Streets projects to reach the $20 million dollar threshold, thus requiring the MPO to amend the LRTP. This event caused the MPO to question whether Complete Streets projects that cost more than $20 million should be included in the MI Program or in the Complete Streets Program, because including them in the MI Program would affect the funding goals for investment programs that were established in the LRTP.


This issue was again discussed at the May 14, 2020, MPO meeting. Discussion points are included below.



After discussion, members expressed support for increasing the threshold amount to $50 million. The Chairman conducted a straw poll asking members if they agreed with that threshold. Most members were in agreement with some preferring no threshold at all.


The Chairman asked staff to provide members with the federal definition of a regionally significant project. This information is provided below.


Federal Highway Administration Guidance

Definition of Regionally Significant Projects

The Federal Highway Administration (FHWA) defines regionally significant projects in its federal air quality conformity regulations as follows:


A regionally significant transportation project is a project (other than an exempt project, see below) that is on a facility that serves regional transportation needs (such as access to and from the area outside of the MPO region, major activity centers in the region, major planned developments, such as new retail malls and sport complexes, etc., or transportation terminals as well as most terminals themselves). These projects would be included in the modeling of a metropolitan area’s transportation network, including at a minimum all principal arterial highways and all fixed-guideway transit facilities that offer an alternative to regional highway travel.


All regionally significant facilities must be included in the travel demand model and any change in capacity to these facilities must be included in an air quality analysis required for federal review. Analyses for the Boston Region MPO are done using the statewide travel demand model, which represents the highway network (including all roadways classified as collectors or higher1) and all Massachusetts Bay Transportation Authority (MBTA) rail and bus lines and commuter boat services.


Exempt Projects

In addition, specific projects are exempt from regional modeling emissions analysis. The categories of exempt projects include:



Staff Recommendation for the MPO Definition of MI Projects

Staff recommends continuing to use the current definition of a MI project as one that changes the capacity of the transportation network but adding, “if it is on a facility that is included in the statewide travel demand model.” This would include all changes to interstate highways, arterials, and collector roadways, and all changes to the MBTA’s fixed-guideway transit facilities. In response to MPO discussions, staff also recommends that the definition changes the threshold cost to projects that cost more than $50 million.

1 This includes interstate highways, arterials (a broad class of roads that include express highways built to interstate standards that are not designated as part of the interstate system), and collector roads (these may not be physically larger than local streets, but they are important because they connect with arterials).