Think bigger on Red-Blue connection
Don’t stop at Charles, extend Blue Line to Kendall
THE RED-BLUE CONNECTOR is back in the news, with the state funding a small study to examine whether the project might be feasible. When we last left it, the connector was tagged with a laughably-high price tag of $750 million for a deep bore tunnel, even though the existing Blue Line tracks extend west to Joy Street, just 1,200 feet shy of Charles/MGH. Since then cities like Seattle have shown it’s possible to bore tunnels for $600 million per mile, or one-fifth the current Red-Blue price tag. Another crack at the project is certainly in order.
But what if we’re not thinking broadly enough? The big selling point of the connector is that it would link Suffolk Downs and the airport to the Red Line, creating an easy connection from Boston’s proposed home for Amazon to the region’s tech hub at Kendall Square. What if, instead of just dead-ending at Charles/MGH, the Blue Line made it to Kendall all on its own?
Part of the difficulty of building the connector is squeezing a terminal station in between MGH and the Longfellow Bridge under Cambridge Street. While a through station requires tracks and a platform, an end-of-the-line station needs more space to function well. Duplicating the Blue Line’s current terminus at Bowdoin—a loop and two “tail tracks”—is much harder just down the street at Charles.
To sweeten the pot, Cambridge could provide MIT a “density bonus” allowing additional office development. Better transit would enable this added density without additional roadway congestion. Given current market rates, a 20 percent increase in office space would be worth more than $25 million in income to MIT every year. That should go a long way towards covering the cost of building and operating the station. Suffolk Downs’ owner could pitch in as well for a direct line to Kendall Square.
Of course, there’s the matter of crossing the Charles, but this might not be as much of an obstacle as it seems. There are no buried utilities in this stretch of river to relocate, which often drives up the cost of projects in urban areas. Instead of boring a tunnel, engineers could dig a trench and sink a prefabricated tube, much like the Ted Williams Tunnel under the Harbor. Unlike the Ted, the river is shallow and doesn’t require a deep shipping lane, and two rail tracks would fit in a much smaller tube than four lanes of traffic. (The Orange Line tunnel between North Station and Community College was built in a similar manner in the early 1970s.)
The sludge on the bottom of the river would have to be remediated, but that would begin the process of removing much of what gives the Charles its “dirty water” image. Costs should be manageable: The Ted was completed in 1995, a decade before the rest of the Big Dig and before the costs exploded.
The Blue Line could run under the Broad Canal, which until 1969 extended through the Volpe site, much as the Red Line runs down the bottom of the Fort Point Channel. This would provide an easy path, free of utilities. On the Boston side, the north half of Cambridge Street was widened in the 1920s. That should provide a reasonably clear shot, free from 1800s-era sewers and utilities, from Joy Street to the river.
Running the Blue to Kendall would provide all the benefits of the Red-Blue Connector at Charles, and more. A trip between Volpe and East Boston would be direct, with no need to climb stairs or ride an elevator to the Red at Charles. Eliminating that transfer would also relieve congestion on crowded Red Line platforms at Kendall and Charles. A much simpler through station at Charles would enable easy connections between East Boston and other stops on the Red Line.
The proposal also gives the Blue Line room to grow. Provisions could be built for future connections to Binney Street and the Grand Junction line that runs through Cambridge to Allston under the BU Bridge. Imagine, down the road, a Blue Line train running from East Boston to Kendall, and then on to Allston and Watertown. Another spur could run in the other direction, using an existing right-of-way that leads to Assembly Square.
Ari Ofsevit is a graduate student at MIT and a member of the board of TransitMatters.