HOW LONG IS too long to wait for all subway lines on the MBTA to be connected?  

100 years?  

This December, it will be 101 years since the Boston Globe first reported on the idea to connect the MBTA’s Red and Blue lines, noting that riders “using either the East Boston Tunnel [the Blue Line] or the Cambridge Subway [the Red Line] could change cars at Charles St, instead of transferring at Scollay Square and Park Street, the most congested parts of the whole system … This would have a distinct tendency to remove this congestion and would therefore be a highly desirable end in itself.” 

A century later, the Globe’s description remains accurate: The Red and Blue lines remain the only two subway lines on the T that do not connect. Riders must make two zigzag transfers, using the Green or Orange lines, to travel between them. Not only is it inconvenient for riders, it also increases congestion and decreases capacity at Park Street and Government Center. These pressures on system capacity will only worsen with time.  

It’s easy to look at the short length of the proposed Red-Blue Connector – less than half a mile – and mistake it for a project with small impact. Nothing could be further from the truth. Connecting the Red Line and Blue Line is a small project with a huge impact, and the time to do it is now, as Massachusetts General Hospital is in the process of rebuilding its campus facing Cambridge Street above the proposed subway connection.  

Today, many of the region’s major job centers and key destinations, like the Longwood Medical Area, Back Bay, and Downtown Boston, can all be reached from every corner of the rapid transit network with at most a single transfer. Employers in these areas (and indeed anywhere along the Green and Orange lines) can therefore leverage excellent transit access to attract talent from across the region.  

Employers in Cambridge, however – including in Kendall Square, one of Greater Boston’s biggest job and innovation hubs – are systemically disadvantaged in this respect. Unlike their peers, these businesses, labs, and schools can’t effectively appeal to some of the densest neighborhoods in the region, in East Boston, Revere, and surrounding communities. Both employers and residents suffer from suboptimal access to transit and opportunities, due to the gap separating the Red and Blue lines. 

Many riders endure this tedious commute nevertheless, straining all other subway lines in the process. As described by the Globe a century ago, these riders have no choice but to squeeze on to already-crowded Green and Orange Line trains, and already-crowded platforms at Park Street and Downtown Crossing stations, all because of this 2,500-foot gap in our subway system. 

The Red-Blue Connector closes this gap. It balances capacity and mobility on our rapid transit network, gives Kendall employers the benefit of better access for potential employees, and gives Blue Line riders better access to jobs in Kendall and elsewhere along the Red Line. Even riders who never set foot on the Blue Line would benefit, as crowding is reduced on trains and platforms throughout downtown. 

The Red-Blue Connector also builds for the future. A total of 10,000 new units of housing are planned for Suffolk Downs, at the East Boston-Revere border: Red-Blue allows Cambridge employers to compete for those workers.  

Suffolk Downs also plans to have office space for 25,000 jobs. Red-Blue makes those jobs more readily accessible by transit to residents along the entirety of the Red Line corridor, from the South Shore, Dorchester and South Boston, to Cambridge, Somerville, Arlington, Belmont, and other communities west of Boston. Cities across Greater Boston are strengthened by connecting the Red and Blue lines. 

But Red-Blue – like all transit – isn’t just about jobs. Extending the Blue Line to the Red Line’s Charles/MGH stop provides patients and health care workers alike direct access to one of the best hospitals in the country.  

Connecting the Red and Blue lines would also cut down on vehicular traffic to Logan Airport. Many travelers using the Red Line, from the entire length of the corridor, are discouraged from seeking access to Logan Airport via the Silver Line bus from South Station as they must endure traffic in the Ted Williams Tunnel. These same travelers often opt for an Uber or Lyft to Logan today.  

With Red-Blue, they would have the benefit of a convenient and reliable two-seat ride to Logan terminal shuttles. No harbor tunnel traffic, no rideshare surge pricing, no missed flights – just convenience via transit. Reducing traffic congestion and emissions in East Boston, an environmental justice community, would be another signature benefit of this long-overdue connection.  

Red-Blue meets the MBTA’s short-term goals of increasing system capacity and resilience, and shouldn’t be thought of as a long-term project. Phil Eng, the MBTA general manager and the state’s interim transportation secretary, in a recent interview, said he supported investments “within our existing infrastructure, [to] build up more resiliency in our system.”  

A new connection at Charles/MGH unlocks additional capacity across the entire system, and enhances resilience by offering redundant transfer points, especially when the Green and Orange lines are suspended for maintenance and upgrades. Connecting the Red and Blue lines fits comfortably within Eng’s vision of supporting rider needs, regional access, and state of good repair. 

Beyond addressing the urgent needs of the present and building for the future, Red-Blue presents an unprecedented opportunity to integrate Mass. General Hospital directly with a new transit station. But Mass General Brigham, MGH’s parent entity, is moving quickly, with work on the second of the new MGH clinical care buildings on Cambridge Street likely to begin in the next 18 months – just around the corner. 

Fortunately, we are not starting from square one. Red-Blue has been well-studied for decades, including as recently as 2021, when its cost was estimated at $850 million.  

In 2018, the Massachusetts Department of Transportation released an update to the 2010 Draft Environmental Impact Report, finding that, unlike many expensive subway projects that utilize tunnel boring machines (TBMs), Red-Blue could instead leverage the cost-effective “cut-and-cover” method.  

Cambridge Street is nearly double the width of the proposed tunnel, significantly reducing utility relocation challenges and providing additional space at street level to accommodate construction. The 2018 update also found that using the top-down cut-and-cover method would enable the full restoration of the sidewalk and roadway early in the process, returning the street to normalcy while work continues underground.  

A well-designed, value-engineered Red-Blue Connector would most likely cost no more than $1 billion through completion. Its significant benefits in comparison – access to key destinations, economic growth, and reductions in emissions – make Red-Blue a low-risk, high-value proposition. 

Municipal and state leaders representing Boston and Cambridge should direct the MBTA to develop a credible plan for completion of the project by 2030. The plan should also aim for 100 percent design and preparation of construction procurement documents as soon as possible.  

Full funding for the project should come from the Commonwealth; waiting or hoping for federal funds, especially in the current political context, is unrealistic and simply a way to delay the project. The city of Boston and the MBTA also need to agree on a location for the connector’s ventilation system – a decision that remains a stubborn barrier to progress – as a matter of urgency. 

Red-Blue has been proposed for at least 100 years. Its profound impact includes better access to jobs, health care, and Logan Airport – a transit access trifecta – for everyone across the region. And the perfect time is now. We cannot afford to wait another hundred years to address a glaring and detrimental gap in our rapid transit network. 

Will Palmer and Elias Fen are co-leads of the TransitMatters Long-Range Transit Planning Group. James Aloisi is a former state transportation secretary.