Silver Line is flawed – but fixable

Silver Line is flawed – but fixable

Improve existing system before adding shuttles, ferries, or gondolas

WITH THE 7.7 MILLION SQUARE FEET of development at Seaport Square approved by the Boston Planning and Development Agency, and a multitude of other development projects filling in further and further from the waterfront, it has become abundantly clear that the current state of Seaport District transit is inadequate to handle present, let alone future, demand.

At Skanska’s 121 Seaport location alone, 400,000 square feet of new office space will house 1,400 workers, of which fewer than 30 percent are projected to drive. The others will walk, bike, and take transit, and while the high non-car mode share is undeniably a positive development, the existing transit system in the area is already overcrowded. Confronted with these issues, a variety of proposals have emerged to solve the capacity crunch — expansion of the fleet of private shuttles from North Station, new ferry routes in the inner harbor, and even a $100 million gondola from South Station to Drydock Avenue have all been proposed. But looking for new, innovative solutions overlooks the best system we have for moving commuters into the district – the flawed, but fixable, Silver Line.

After having some of the lowest ridership per station in the entire MBTA for its first 10 years, rapid development along Seaport Boulevard has caused a spike in Silver Line utilization. With current service levels, this results in bad frequency, slow trips, and users being left behind on the platforms due to overloaded buses. While the existing Silver Line is badly overstressed, the “bones” of the line – the physical infrastructure – are far superior to any proposed alternative system for Seaport transit.

The Silver Line Waterfront service runs in a grade-separated transit tunnel, arcing from South Station to Seaport Boulevard and then back south toward the Convention Center. The stations are large, with arrays of fare gates and full-length mezzanines. The pedestrian visibility is good, with multiple station entrances to maximize the walkshed of each station. Service is operated by dual-mode busses that operate emission-free in the tunnel, then turn on diesel engines to continue to Logan or Drydock Avenue.

At the other end, at South Station, riders can transfer free of charge to the Red Line via an indoor, accessible station complex, with the commuter rail on the level above. The flaws of the existing system come not from fundamentally bad infrastructure, but from low capacity and frequency. Implementing two simple enhancements to the Silver Line should be the first priority of those who want better waterfront transport access. For less money than a gondola or ferry, and with more equitable access than private shuttle buses, Boston can and should build a higher-capacity, faster Silver Line.

The first fix simultaneously makes trips faster, increases frequency, increases capacity, and costs negative dollars. On the outbound route to Logan, Silver Line busses must follow a complicated backtracking route to enter the Ted Williams Tunnel. However, there exists a much faster entrance. Directly after leaving Silver Line Way, SL1 busses could simply make two right turns and find themselves on a bus-only on-ramp, cutting minutes off their trip time.

The dedicated on-ramp bypasses the bulk of tunnel traffic, which is at the previous ramps, creating an analog version of bus priority. Unfortunately, the Massachusetts State Police have taken over this ramp and refuse to provide access to the MBTA. There is no credible reason for preventing use of this ramp by MBTA busses. (When portions of the tunnel access points to the Williams Tunnel were closed following the tragic failure of a portion of the tunnel ceiling in 2005, MBTA busses were allowed to use the ramp.)  The record shows that there was no impediment to the operations of the State Police because of this shared use.

The most cost effective improvements should be pursued first, and convincing the State Police to let the T use a ramp that already exists should cost nothing at all. Gov. Charlie Baker could make this happen with a meeting and the stroke of a pen. If implemented, SL1 busses would reach Logan and complete their trips faster, which would boost frequency along the entire route as buses returned early. Since capacity at peak times is directly proportional to frequency, the routing change will help solve one of the biggest problems with Seaport transit for no additional cost.

The second fix is perhaps the most fundamental one. The Silver Line is too popular for its current fleet of buses, so the T should order more. The infrastructure of the tunnel, with massive stations and long platforms, is clearly capable of handling increased service. In fact, the original conception of the line involved platoons of three busses traveling together. While such an expansion of the line’s fleet would have been wasted during the Silver Line’s first decade of operation, the ongoing boom in development, especially peak-oriented office buildings, has substantially overstressed the existing system.

While the dual-mode buses in current use are expensive and hard to source, the most overcrowded portion of the line, the waterfront tunnel, can and has been served by simple electric trolleybuses such as those used in Cambridge. The MBTA should promptly procure an expanded fleet, freeing up dual mode buses for SL1 and SL2 service. If this capacity is still not enough, the T could electrify the entire SL2 service, from its existing changeover at Silver Line Way to Drydock Avenue, and use all of its specialty buses for airport service. While neither investment is free, electric trolleybuses cost on the order of $1 million per unit, meaning that with only Seaport Square’s planned $2.5 million per year contribution towards district transit, rapid fleet expansion should be possible.

If the first two solutions still leave seaport transit overcrowded (and there is plausible reason to believe they may, at least in the long term), then the Massachusetts Department of Transportation and the city of Boston should look at higher-cost capital fixes. The largest of these deals with the single point where the Silver Line Waterfront service intersects with private traffic – the D Street light. Existing service frequently has to wait for up to a minute to cross the intersections, and the existing light only permits two buses per direction per cycle to pass.

Future frequency increases risk forcing every bus to wait at least one full cycle, a particularly extreme version of bus bunching. While the complexity of construction would likely force a closure of the existing Silver Line service for several months, if the line truly begins to exceed the capacity bought with the two previous improvements, the MBTA should bite the bullet and construct a bus tunnel under D St, rising up to meet the existing Silver Line Way Station. The cost, likely at tens of millions of dollars, is far higher than previous solutions, and should thus be pursued after other organizational and fleet changes. However, the improvement leverages the existing, much larger investment in the transitway tunnel, and is thus likely to be more cost effective than any new transit system, which must reinvent the entire route.

Of course, there are other bus-oriented transit fixes that must be considered to bring transit mobility in the Seaport District to the place it ought to be. The MBTA has committed to improving service on the 7 bus. The advocacy group TransitMatters has proposed a new bus rapid transit service that would connect South Station to the Boston Convention and Exhibition Center, Logan Airport, the Flynn Maritime District, and South Boston along the First Street corridor, taking pressure off the existing Silver Line service and providing better bus transit in a currently underserved (and increasingly residential) corridor. These improvements ought to go forward as necessary complements to the Silver Line enhancements I have proposed here.

Meet the Author

Ted Pyne

Leader of outreach and recruitment efforts to college students, TransitMatters
While the Silver Line in its current form is obviously inadequate, its inadequacy comes from insufficient capacity, not a fundamentally flawed design. Seaport planners and developers should recognize its potential, and push for prompt, cost-effective enhancements to the Silver Line over ferries, gondolas, or private shuttles.

Ted Pyne is a member of TransitMatters and leads its outreach and recruitment efforts to college students in Massachusetts.

  • Mhmjjj2012

    I’d like to know when and why the State Police refused the MBTA access to a ramp. How was the decision made? Who exactly made the decision? Was there a public hearing? Was MassDOT consulted?

  • bluishgreen

    I’ve never understood the exclusivity of that State Police ramp either.

    In terms of the number of SL buses — are they still doubling the number of SL1 buses as part of the mitigation for the parking garage expansion at Logan? Was that officially approved or still just a proposal? Plus, aren’t the new buses form the upcoming Chelsea SL also going to make the Seaport SL1 stops? If so, wouldn’t the two of these together greatly help with the capacity within the Seaport stops (except the SL2 stops)?

    • TedP

      At rush hour, the new Chelsea SL3 trips will be “converted” SLW trips, so AFAIK the number of buses in the waterfront tunnel will remain the same.

  • Adam Peller

    It has been discussed much in the past, but is TSP really impossible for D-Street? Is there no better tweak to the signaling than an 8-figure tunneling project?

    Also, the Silver Line has the distinction of being the only transit line I can think of that stops twice at the same stop (inbound, World Trade Center). Once above ground, then below. The actual route is horribly inefficient. Is there any potential for improvement here? Why not just skip the above ground stop?

    And what about laying tracks in the tunnel, according to the original plan? What’s the cost/benefit over continuing to invest in buses?

    • TedP

      It’s possible, but trying to build a signal cycle that works for 30 buses per direction per hour, especially with heavy bunching in the TWT, starts running into real capacity constraints eventually. The cost of a tunnel does make it the last improvement to invest in.


    One question and one grip.

    The question: why were such large underground stations built? A public basketball court could be set up on the main level at Courthouse station without impinging on strap hangers moving through this part of the station.

    The grip: Signage for the Silver line SUCKS.

    For example, the World Trade Center is noted on Silver Line signage at South Station, but there is no ready/obvious mention of how the Convention Center is also serviced by the World Trade Center Station. Recorded announcements on buses advise riders of this, but why is there not some basic/better signage noting same?

    Also, Courthouse Station does not have much, if anything, which tells passengers which way to the Federal Courthouse. Such was not such a big deal when courthouse was easy to see when the Seaport District was just starting to develop if one errantly exited from one of this station’s more distant exit points from the courthouse, but now the courthouse cannot be seen when one exits ANY of the Courthouse station exits. Such also makes things difficult for those heading to other venues in the immediate area as frames of reference are few and far between unless one is a regular Silver Line user and knows the area.

    • TedP

      The MBTA had some egregious cost bloat in the SL tunnel project- the large stations are a great example. Fortunately they’ve stopped building pointlessly overbuilt designs with the GLX and SL to Chelsea extensions.


        Only “some” bloat?

        Oh and now the MBTA has moved onto dumb – the current plans for a new station at Quincy Center include all sorts of inane station changes to accommodate a so-called Transit Oriented Development and score some air rights lease revenue but which will most likely prove to be BOTH a net money loser for the T as well as which WILL thoroughly Q-up traffic on Quincy’s main crosstown arterial roadway.

        • Ed Cutting, Ed. D.

          The Montparnasse crash (pictured above) was caused by excessive speed, not poor design.


            With all due respect, design and speed are interwoven. Plus, this picture is great for underscoring things.

          • Ed Cutting, Ed. D.

            If truck & bus drivers are held responsible for speeding, why not train drivers?


            Two points. One is that speed violations by a “train drivers” is not germane issue as regards this Commonwealth article. And the other: train engineers can be held responsible; for example, they can be fired depending on the circumstances..

          • Ed Cutting, Ed. D.

            Two points: Speed was the cause of the accident you depicted, and being fired would be the least of the concerns of a bus driver who killed passengers by going twice the posted speed.
            Someone who rolled a bus because he was going 80 MPH around a 30 MPH curve, or 110 MPH around a 50 MPH curve would be in jail.


            Clearly, you do not appreciate the use of metaphors. SMH.

    • Ed Cutting, Ed. D.

      In fairness, the Mattapan Trolley is using old equipment on a line that (I believe) would have to be rebuilt to run LRVs. Good point on Red/Orange/Blue lines — in fairness, the Blue Line needs to switch between 3rd rail and overhead wire, but otherwise…. And state law requires ALL railroads to be standard gauge…


        First off, I love PCC cars and thus am open to cutting the Mattapan Trolley some slack even if the Q screwed up on making its track turnaround radius at Ashmont too tight. Also note that PCC cars are in regular use in a number of transit systems as – properly maintained – they can both run all but forever as well as be cost-effective. Mattapan’s real problem is that it is but a short line operation.

        The other four rail lines with not interchangeable rolling stock – and which includes very different models of trolleys on the Green Line – AND trolley buses for the Silver Line, however, are daily reminders of just how often some really wicked dumb decisions have been inflicted upon strap hangers.

        • Ed Cutting, Ed. D.

          I don’t see why Red & Orange aren’t interchangeable. Both were built by the BERy as heavy-rail subways. It’s largely a zero-sum game, as a car on one line isn’t on the other, but still…


            Among other things, different car lengths. While a far number of parts are interchangeable for maintenance, the differences make interchangeability as regards use not a viable proposition.

  • jhersey3

    How about a dedicated bus lane through the tunnel? Free ride from Logan to South Station is useless if a bus full of riders sits in traffic next to SOVs. Even more important with Silver Line Extension to Chelsea.


    Bus Rapid Transit (BRT) LOL. It’s not Rapid, it’s not Transit, it’s a FREAKING BUS!!! The original plan for the Silver Line, and rationale for the tunnel from South Station, was for RAIL. Want to fix the Silver Line – convert it to rail and extend it underground in the Seaport district. Blue Line should be primary rail solution to airport.

  • BostonsBill

    One of the major SL1 problems is how they handle the Logan terminals loop. Buses should drop off passengers on one pass, then begin to pick up on the second pass and head back to the city. If you ever watch time/motion of people with luggage try to jockey with bags for the next stop it’s a total waste of time, and makes everyone anxious about missing a stop. Logan Express from all directions does this and it works. Having the SL1 bus simply be drop off only on a swing through, then after terminal E make another pass to load up wouldn’t add a lot of time, but make the system way more customer friendly.

  • BenSahn

    This is a really important discussion. I take the Silver Line to and from the airport, using the Red Line in each direction — and the Silver Line bus to/from is way too slow, often off schedule, and often overcrowded. The last time I was at Logan, we waited more than 10 minutes, and no Sliver Line bus, with the bus timer announcement amazingly reset from next bus arriving in 5 minutes to arriving in 10 minutes. Also, there were so many people waiting for the bus that not everyone could board. We eventually jumped on a bus to the Blue Line and then did Green Line to Red Line and think we came out ahead. That is not how it is supposed to work.

    In addition to the suggestions made in the article, I think we need to get the T to do the Red Line Blue Line connector at Charles St. That would also relieve congestion on the Silver Line because people like me who are going to/from Alewife on the Red Line would happily use Red Line/Blue Line transfer at Charles St., rather than be part of the snail-crawl on a Silver Line bus that is often overcrowded.