MBTA officials eye connecting Red and Blue lines

The MBTA's extension of the Green Line is finally set to open next month, and transit advocates are looking ahead to see if there's hope for another long-stalled T expansion project: a link between the Red and Blue lines in the heart of downtown.

The big picture: The Blue and Red are the only subway lines in the MBTA system that don't intersect. A plan to connect them has existed in one form or another for nearly a century.

Why it matters: Aside from finally linking the entire system, easier access to Logan Airport via the Red Line would benefit the growing life sciences sector in Cambridge.

• It would help alleviate Logan-bound road traffic in East Boston and link major housing developments around Eastie with the growing job centers and universities along the Red Line corridor.

MassDOT's plan to connect the two lines calls for digging a tunnel between the Bowdoin Street terminus of the Blue Line under Cambridge Street to the Charles/MGH Red Line station.

• The MBTA estimated last year the project would cost $850 million.
• The tunnel would be built directly under Mass. General Hospital's Cambridge Street-facing front while the hospital renovates its West End campus.

What they're saying: "I think we have to move because MGH is moving and they want to be partners in this," East Boston Sen. Lydia Edwards told Axios.

• Mass. General Brigham, the hospital's owner, did not respond to questions about its support of the project.

Reality check: Promoting the connector plan from the back burner to a marquee project will take political will and public resources at the same moment a new governor takes charge of the state's transportation priorities.

• Gov.-elect Maura Healey lists the Red-Blue connector among seven major transportation infrastructure projects she supports.
• Her campaign website says she's "committed to taking the necessary steps to ensure these projects go from ideas to reality," but the site only specifies commuter rail service to western Mass. as a priority.
• A spokesperson for Healey's transition team declined further comment.

The bottom line: The state is flush with tax revenue, federal COVID relief dollars and will begin to see even more money come in from the higher tax on incomes over $1 million that goes into effect next year.

• Edwards says the Blue-Red connector is one of several major projects that will be competing for attention and investment as the new governor and lawmakers make decisions on what to build.

Many in the Cambridge business community see a swift connection to Logan and more housing options north of the city as crucial.

• "People who live north of Boston in communities serviced by the T - so that's Lynn, Revere, Everett - would be able to access Kendall and the many innovation leaders we have here with just one transfer and that's a game-changer for us," Kendall Square Association executive director Beth O'Neill Maloney told Axios.

Flashback: After laying dormant for most of the 20th century, the state committed to the connector plan in 1990.

• Twenty years later, designs were drawn up during Gov. Deval Patrick's administration but abandoned due to a lack of funding.
• MassDOT updated its concept and design in 2020 and included a new station entrance at MGH as part of the plan.

What's next: The current proposal would take at least eight years to complete.