Somerville’s Green Line Extension

By Matt Bornstein

Last December, Boston’s public transit authority began construction on an extension of the Green Line light rail system.  Today, the Green Line runs from the near western suburbs, through downtown Boston, into East Cambridge.  The planned expansion would add seven stations serving Somerville and Medford, Cambridge’s neighbors to the north.  (See map; the extension is marked as a dashed green line.Bornstein 1

If you are an average HBS student, your response to this news is probably, “what is the Green Line?”  For a typical Boston resident, the reaction is probably more like, “why extend the slowest, most cramped, least reliable public transit line in the country?”  In Somerville, though, this project has people buzzing and emotions flowing.

Home to about 80,000 people, Somerville is the most densely populated neighborhood in Boston and among the densest areas in the country.  Historically, its residents were working class and diverse (for Boston) at “only” 70% white.  In the mid-1990s, however, gentrification hit.  Condos, restaurants, and shopping areas began to move in.  Property values quadrupled from 1991-2003.  Long-time Somerville residents came into contact with new yuppie entrants and, worse, a massive wave of young hipsters.  The causes?  Many, including urban expansion, the repeal of rent control, and thriving businesses in nearby Cambridge and along I-95.  The trigger?  The Red Line subway added one stop in Somerville.[1]

You can see, then, why seven new stations are a cause for controversy.  Most residents – or at least the most vocal – support the project and have berated the state for delays.  Lawmakers, including the governor and local congressman, are touting the recent groundbreaking as a major success.  Long-time Somerville residents, however, are on the fence.  And looking below the surface reveals the usual brewing disaster of a Boston public works project.

The Green Line extension is currently slated to be completed in 2019 at a cost of roughly $1.3Bn.[2]  Sounds reasonable for a project of this scale.  But there are a few problems:

  1. No one knows who will pay for it.  The state is seeking ~$550M in financing from the federal government, money which is by no means guaranteed.  The balance (~$750M) is expected to come from state bond funds which have not yet been approved.  Meanwhile, the MBTA is facing revenue shortfalls and the Mass. Department of Transportation is fighting an uphill battle for moderate increases to its operating budget.  Public-private partnerships are being put to good use (e.g., real estate developments near stations in exchange for needed right-of-way) but will not meaningfully reduce the $1.3Bn figure.  (More financing details here.)
  2. Construction started two months ago, and it’s already five years behind schedule.  The state is legally obligated to complete this project by 2014, a deadline imposed by a Big Dig lawsuit.  Right now, though, 2019 looks optimistic.  As a result of the delay, the state must simultaneously pursue other, near-term environmental improvement projects.  This has the potential to dramatically increase costs and create a vicious cycle of further delays caused by distraction and diversion of resources.
  3. Political cover is shaky.  Massachusetts Governor Deval Patrick has championed this project as a tangible part of his legacy.  Rumors are circulating that Patrick may leave his post in 2013, though, to fill a spot in the US Senate or another federal position.  If he departs, the project could face even steeper delays.  At the December groundbreaking, Congressman Michael Capuano was quoted as saying, “We need to get as much of this project done and committed in an irrevocable way before [Patrick] leaves office.”

The ingredients are there for this to become an albatross around the neck of the next governor.  It’s hard to argue against increased mobility and reduced pollution in Boston’s most densely populated neighborhood.  But whether the project will become another public works sinkhole – and drive out the last of old Somerville – remains to be seen.

Bonus: Boston’s own “MRT vs. BRT” evaluation process ( light rail vs. BRT vs. commuter train)

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Table: Tier 1 Green Line Extension Alternatives Analysis (Source: GLX project)

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Table: Tier 2 Green Line Extension Alternatives Analysis (Source: GLX project)

[1] Wikipedia & local knowledge

[2] “Preliminary Engineering Approval for the Green Line Extension (GLX) Light Rail Transit Project,” 6/11/2012


Sustainable Southern Systems: Developing Mass-Transit Solutions for the American Southeast

By John Clayton

The Southeastern US continues to see significant population growth, clustered not just in large cities such as Dallas, Atlanta, or Houston, but increasingly in mid-scale cities such as Charlotte, Austin, and the Research Triangle region. Migrants to the region are pulled by a relatively high quality of life at a low price tag, fueled by large inventories of cheap housing. When coupled with a lack of natural land barriers, denser development is inherently discouraged in favor of massive urban sprawl. As the attached graphic shows, Atlanta is home to a population roughly equivalent to Barcelona’s, yet has a 20x larger geographical footprint. Raleigh has an average density of 4 people per square hectare compared to Barcelona’s 176 people. Given such sprawl, what type of transit solution could possibly work?

As we discussed in the Bogota TransMilenio case, large metros work well and can be sustainably financed in a handful of mega-cities (Seoul, Shanghai, Singapore), particularly when strong government can derive additional funding sources from rising land values around metro stations. BRT systems offer less capital-intensive solutions, but may be less palatable to a population with high car ownership rates. Light rail is a lower-cost alternative to heavy-rail systems in major urban areas, both less expensive than traditional metro systems yet differentiated enough from existing transit options to convert drivers.

Applying light rail transit systems to less dense cities, however, is tricky: it requires connecting existing higher-density nodes (universities, shopping complexes, downtowns) with green- or brownfield spaces that can channel future high-density development. Charlotte’s new Lynx light rail system offers an excellent example of the ideal mix of transit stations: it connects highly-trafficked areas such as Uptown, the convention center, and Southpark Mall, with previously undeveloped tracts of land; it then worked with developers to incentivize the construction of residential, commercial, and retail units around each station.

Assuming a city finds a suitable transit system, the most significant obstacle still remains: the financing hurdle. Faced with a populace generally skeptical of increased taxes and local government largesse, cities should turn to innovative financing schemes to help offset the infrastructure and operating costs. As our discussion of Hong Kong’s system highlighted, planned urban infill offers three key benefits: 1) it builds city density, thereby reducing sprawl; 2) it clusters residents around the transit stations, diverting more traffic and increasing ridership rates; and 3) it causes land values in surrounding areas to appreciate.

To harness this financing opportunity, cities should design transit systems that both connect high-traffic areas and traverse undeveloped land tracts, then enter into public-private partnerships with developers to build high-density mixed-use neighborhoods. Such collaboration would not only allow governments to capture a slice of increased land values, but also directly influence features such as below-market housing units and city infrastructure such as schools.

Of course, such a partnership would have its share of skeptics. Many Southerners are skeptical in general of government involvement in projects and unfamiliar with PPP schemes, and could perceive a government conflict of interest in development promotion. These concerns could be assuaged by a public relations campaign and consultations with PPP experts. Coupled with long-term development plans that continue to prioritize smarter, higher-density development, Southern cities from low-density sprawling giants to sustainable transit meccas.

Clayton Atlanta Barcelona


Comparison of the geographic footprint of Atlanta and Barcelona (source: Alain Bertaud,