Wednesday, October 16, 2013

Casey Arborway - A Briefing in Support of the At-Grade Solution

To download a pdf of this briefing:


  • The Casey Overpass in Jamaica Plain is beyond repair and must be demolished for public safety
  • Offers an historic opportunity to reconnect broken portions of the Emerald Necklace and improve livability through contemporary urban and traffic planning
  • For nearly three years citizens, neighbors and other advocates have participated in an open process with MassDOT professionals to design a replacement. Twenty-two Advisory Group meetings were held and seven larger Public Hearings took place to update the community.
  • MassDOT selected an At-Grade Solution, a simplified network of surface roads in March 2012 and the majority of the community hailed the choice
  • Peer-reviewed traffic projections indicate no significant drop in level of service for any affected routes, and some improvement for many. Air quality analysis shows no change.
  • Significant opportunity to improve multi-modal access for cars, bicycles, and pedestrians to the area parks and businesses
  • Enhanced access to MBTA services: a new head house and upper bus way.
  • New and enhanced plazas north and south of Casey Arborway could accommodate festivals and farmer’s markets
  • Improved civic space at the West Roxbury District Court
  • A tree-lined boulevard and coordinated lights replace a crumbling bridge
  • Construction and maintenance cost savings are estimated to be at least $20 million if the bridge is not replaced
  • Planning and design is nearly final
  • Opportunities for Elected Official leadership in constituent services, construction mitigation, adjacent-area improvements, economic development
  • Demolition scheduled to begin in spring 2014, construction to last until fall 2016


The Monsignor William J. Casey Overpass was built in the early1950s on a portion of the Arborway parkway of the Emerald Necklace in the Forest Hills section of Jamaica Plain. Due to flaws in its original design and the deterioration of its structural integrity over the last 60 years, it is now beyond repair and must be demolished. For safety, vehicle traffic has been reduced to one lane in each direction for more than two years (from the original six lanes) while a replacement solution is designed. The community outreach and design process undertaken by MassDOT and its partners the City of Boston, DCR and MBTA has been ongoing for nearly three years to date. Engaging hundreds of professionals and local citizens in dozens of public meetings, the plans have been improved and have incorporated community input to the extent possible at every juncture. Demolition of the Overpass is scheduled to begin in the spring of 2014. The project will be completed in Fall 2016.

The Jamaica Plain, Forest Hills, Roslindale and West Roxbury neighborhoods in the shadow of the overpass are characterized by an abundance of greenspace and recreational opportunity, by an inviting mix of residential properties and vibrant commercial enterprises, by active community engagement in schools and other civic life and by access to convenient public transportation. Boston’s world-renowned Emerald Necklace parkways, Southwest Corridor Park, Franklin Park, and the Arnold Arboretum are immediately adjacent to the project, as is the Forest Hills MBTA station.

Forest Hills has been an important transit hub for nearly 200 years. When the Overpass was built, its huge ramps, supports and abutments spanned three different rail lines. A heavy rail embankment crossed the bridle paths and carriageways of the Arborway atop a handsome, five-arched bridge from the 1890s until it was torn down in 1986. The street-level Arborway trolley line made its way under this viaduct from South Street to the Arborway Yard from the 19th century until the mid-1980s.  The elevated Orange line ran above Washington Street on steel beams and huge concrete posts from the 1910s until 1986, culminating in a large station that served the El above, trolleys, buses and cabs below.

The Casey Overpass leapt over all this, as well as Washington Street, Hyde Park Avenue and South Street – major north-south thoroughfares for the surrounding neighborhoods.
The span of the Overpass, with its huge piers below, was built on the land that once carried eastbound Arborway traffic from Boston. It bypassed rail and trolley congestion below, and was built for vehicles going to and from Mattapan, Dorchester, Quincy and Milton. All local traffic seeking the businesses and residences of southern Jamaica Plain, Forest Hills, Roslindale, the Walk Hill and Bourne neighborhoods or the West Roxbury District Court was required to exit the Arborway and wind through and around these piers and ramps via convoluted and inefficient paths that disrupted the flow of traffic on the ground further, requiring transit of as many as four traffic lights for what should be simple and routine pathways.

More than twenty-five years ago the Orange line and the heavy rail lines were brought together and sunk below grade in the Southwest Corridor Trench. A new MBTA station was built and the old station and granite viaduct of the New Haven line were demolished. The Arborway trolley ceased operations at the same time. This mid-1980s transformation of Forest Hills eliminated the surface congestion of the three rails lines that the Overpass was built to span. The Overpass ramps and supports continue to impede street-level traffic, as they have since the 1950s.


National and international urban planning initiatives have for decades called for a more equitable access for all transit modes, and Boston’s planning has been no exception. As Mayor Menino has stated, “The car is no longer king in Boston.” All across the country cities, including Boston, have been saying “No” to building or replacing urban overpasses that divide neighborhoods and increase the tax-funded maintenance burden far into the future.
Boston’s own Complete Streets approach puts pedestrians, bicyclists and transit users on equal footing with motor-vehicle drivers. The initiative aims to improve the quality of life for Bostonians by creating streets that are both attractive public spaces and sustainable transportation networks. It embraces innovation to address climate change and promote healthy living. The objective is to ensure that Boston's streets are:
  • Multimodal: Incorporates pedestrians, people with disabilities, bicyclists, transit users, and motor vehicle drivers. Roadway design includes level of service benchmarks for all modes to ensure that streets are shared by all users and not dominated by cars.
  • Green: Incorporates street trees, rain gardens, green margins, and paving materials with permeable surfaces so that plants and soils collect rainwater to reduce flooding and pollution. Green design elements promote an environmentally sensitive, sustainable use of the public right-of-way.
  • Smart: Incorporates intelligent signals, smart meters, electric vehicle sharing, car and bicycle sharing, way-finding and social networks for greater system efficiencies and user convenience.
MassDOT’s GreenDOT initiative, begun in 2010, has goals aligned with Boston’s Complete Streets and with contemporary planning tenets. It has a mode shift goal of tripling the share of travel in Massachusetts by bicycling, transit and walking by 2030.


The Casey Arborway Project has enlisted hundreds of local citizens and engaged thousands more over nearly three years in an open, collaborative process that has considered all of these aspects in an effort to find the best possible solution for this complex 21st Century transportation and urban planning opportunity. The professionals, advocacy groups and ordinary citizens all agree that the Casey Arborway replacement provides
  • A once in a generation opportunity to improve the efficiency of travel and access to the area for all modes (car, pedestrian, bike, public transportation)
  • A once in a lifetime opportunity to enhance livability through improved civic spaces, enlarged greenspaces, and a restoration of the Emerald Necklace in Forest Hills – a recreational connection that has been broken for a century.
  • The chosen At-Grade solution has the active support of parks, livability, and cycling advocacy groups who have offered their expertise throughout the planning process: Emerald Necklace Conservancy, Walk Boston, Boston Cyclists Union, LivableStreets, Arborway Coalition.
  • These groups are engaged with tens of thousands of Bostonians who care deeply about all these issues – parks, open space, pedestrian and cycling access, public transportation - and they applaud the Casey planning work that has been done so far. Their active input and that of local citizens and neighbors of the project has been invaluable in improving the outcome and in encouraging MassDOT to embrace this historic opportunity. 


            The Casey Overpass was a poor design from the start, with hammerhead piers that have decayed severely and drainage schemes that have further contributed to deterioration. Critical repairs were conducted in 1980 and 1991. MassDOT maintenance inspections determined in early 2010 that the Overpass load rating must be reduced to 14 tons. It was found that reducing traffic to one lane in each direction and moving traffic away from the outer lanes and towards the center for safer operation was the best option for achieving necessary load reduction. In December 2011, it was determined that the Overpass was in “critical to fair” condition, and nearing the end of its serviceable life. The planning process for its replacement was begun.
            A Working Advisory Group (WAG) comprised of citizens, neighbors and advocacy groups representing neighborhoods, parks, cycling, and livability was formed to augment and advise the professional planning processes. This open and public committee met more than twelve times, and five larger Public Hearings were held in the community before MassDOT announced a final decision on a replacement approach. Scores of different alternatives were evaluated, including those suggested by members of the WAG and the general public.

Baseline traffic data was acquired during this process for the Overpass itself and 17 intersections in the area in early June 2010, while the Overpass still had two open lanes in each direction.  The average weekday daily volume for the Overpass was found to be 24,000 cars (both directions, all day). New Washington Street below was found to have an additional east-west volume of 12,000 cars per day.
It was known that an overpass could serve traffic loads in the area, but any other alternative needed thorough study. The traffic data was projected out to the year 2035 using accepted projection methodology. Travel routes, transit times and circulation patterns throughout this complex area were measured and evaluated in a point-to-point matrix, projected into the future and then applied to both an improved at-grade street arrangement and a two-lane replacement overpass. The data collected and methodology used was peer-reviewed by outside transportation experts.
Both plans showed improvement over the current overpass and street configuration. But through this data testing process it was determined that drivers would experience no significant degradation or favorability in service with either plan. The levels of service for some routes showed marginal slowing (30-45 seconds), while the majority of routes were either time and distance neutral, or marginally improved.
Because of the comparable travel times and distances, Air Quality analysis showed no predicted degradation in air quality.

The cost projections provided by consultants, however, showed a very significant difference between the two alternatives under consideration: an estimated $74 million cost for a new overpass (plus substantial future maintenance obligations for the 75-year life of the structure), or $54 million cost for an at-grade configuration.

MassDOT announced its decision to select and develop a so-called “At-Grade Solution” to be known as the Casey Arborway in March 2012. The existing ramps, abutments and supports of the Overpass will be replaced by a simplified series of intersections on the ground using coordinated lights, a plan that offers significant opportunities to return the area to human scale and enhance livability for residents and visitors alike.
MassDOT immediately formed a new Design Advisory Group (DAG) to consult on the planning, to voice community concerns and to refine project priorities. The DAG met ten times over 18 months, and focused on a variety of important topics at each meeting. Additional public hearings were held to update the larger community at the 25% and 75% design stages, to hear concerns and to report on progress.


  • The creation of a tree-lined boulevard where the unsightly shadow of a crumbling overpass now stands.
  • Simplified turns and north-south routes throughout Forest Hills with coordinated lights directing the flow of traffic.
  • A new MBTA head house on the north side of the Casey Arborway, which will provide direct access to the Orange line platform without crossing what is now New Washington Street.
  • A new northern Plaza at the end of Southwest Corridor Park, which provides significant civic space suitable for gatherings, festivals, farmer’s markets and community events.
  • An enhanced entrance plaza adjacent to the MBTA station on the south side of Casey Arborway will provide improved waiting and gathering space as well as room for retail kiosks.
  • The #39 bus terminus will be relocated to an expanded upper bus bay along Washington Street.
  • Significantly improved civic spaces in the District Court House area.
  • Dedicated bicycle and pedestrian paths and crossings throughout the area
  • A strengthened and more accessible connection from Franklin Park to the Casey Arborway, Arnold Arboretum and the rest of the Emerald Necklace parks, as well as to Southwest Corridor Park.
  • Enhanced way-finding for visitors and residents navigating the area on foot, by bicycle, by public transportation and by private vehicle.
  • Increased access to the world-class recreational opportunities and the vibrant businesses of Forest Hills and Jamaica Plain.

The Casey project planning has also included significant regulatory review.  Environmental Justice and Air Quality reviews were conducted and Massachusetts Environmental Policy Act certification was achieved.
MassDOT and the Massachusetts Historical Commission are currently considering a finding of ‘adverse effect’ in the preferred plan at Shea Circle. Shea Circle has one of the state’s highest rates of single-vehicle car accidents, and MassDOT has proposed to create a signalized intersection known as “Shea Square”. This proposal provides significant traffic calming as well as a configuration that is more serviceable for pedestrians and cyclists while expanded the acreage of useable greenspace. The DAG and the majority of the local community has valued public safety and enhanced access to Franklin Park over the existing large traffic rotary, which has no traffic lights and little traffic calming effect. But Shea Circle, a feature not part of Olmsted’s original design and not built until the 1930s, is in fact part of the Morton Street Historic District, on the National Registry of Historic Places and subject to MHC review. The outcome of this consideration has yet to be determined as of this writing.


MassDOT’s final design is nearly complete. Construction phasing and detouring plans have been outlined. Landscaping schemes are being refined. Major features – the plazas, bus ways, bicycle and pedestrian paths and major intersections – have been designed. Provisional construction blue prints have been prepared. MassDOT is making final refinements through an internal review process, will host a final DAG meeting and then intends to advertise the project and solicit bids in October or November 2013. Construction is expected to begin in the spring of 2014 and be completed in the fall of 2016. Any significant changes to the plan at this point could substanially increase the cost of the project and could result in increased safety risks.



Demolition and construction/mitigation management 

            During any construction project as large as this one - immediately adjacent to residential neighborhoods, retail and commercial enterprises and a thriving transit hub - there will likely be issues requiring strong leadership:
  • Education, information and preparation concerning Construction Phasing
  • Sound and dust mitigation, hours of construction, planned detouring and closures
  • Policing: Traffic management, parking and speed enforcement, signage
  • MBTA and school bus service levels and contingencies
  • Constituent services/Hot-lines
  • Disruption and traffic delays would occur no matter what the replacement design

Planning for adjacent features

Consideration should be given to improving adjacent city-owned properties to leverage final outcome:
  • “Don’t Block the Box” signage and striping on South Street at Arborway Road
  • Sidewalk improvement along Forest Hills Avenue adjacent to the Arborway Yard
  • DCR should construct the long-planned pathway through the Arborway Hillside, from South Street to the Arboretum as outlined in the 2008 Gateway to the Arborway plan.

Housing and economic development

The future Casey Arborway and Forest Hills’ proximity to mass transit is making the surrounding area a magnet for new housing and commercial development.  While this will provide much-needed new housing and job opportunities, it also presents challenges for elected officials. 
  • Private development will need to be coordinated with the state’s construction schedule for the Casey Arborway and residents will look to the City to provide both enforcement and a vision for the neighborhood as it evolves.
  • In 2008, after a lengthy community process, the BRA released the Forest Hills Improvement Initiative, which provided development guidelines for MBTA and private property.  Two of those parcels have already been developed as commercial/office space and a third is slated for new housing and retail.   Additional proposals are currently under review to convert former industrial sites along nearby Washington Street to housing, retail, and commercial space. 
  • Parcel U (along Hyde Park Avenue) is slated for retail and housing. Developers of the former Hughes Oil site are seeking zoning approvals with an emphasis on desirability of multi-modal transit access dependent on improved traffic patterns, diversity, mixed-use, community spaces, as well as improved greenspace and recreational access.
  • Neighborhood residents have requested additional planning to guide new development adjacent to the north side of the Casey Arborway, which was not included in the FHII.
  • The existing MBTA Arborway Yard facility has been envisioned as home to a new MBTA bus yard. The state has agreed to provide 8 acres of land to the City of Boston for housing, commercial use, and open space. Elected officials will need to be a strong advocates for state funding to bring the project to fruition, as well as work with the neighborhood to plan for its redevelopment.

The Casey Arborway Project offers an unprecedented opportunity to bring positive change to several of Boston’s premier neighborhoods. By reconnecting long-broken links within the Emerald Necklace parks and by providing enhanced access for pedestrians and cyclists that fulfill the promise of Southwest Corridor Park, the Casey Arborway and Forest Hills will become a citywide recreational magnet, an attractive locale for retail and housing development, as well as a much-improved version of the transportation hub it has been for more than a century.


For a complete record of all public meetings, including meeting minutes, attendees, public comment and professional presentations:

Many relevant documents, reports, data and long-range planning resources related to the project are collected here:

Participants and partners in the WAG and DAG process are here:

For a pictorial history of the Arborway and Overpass at Forest Hills:

A complete history of Forest Hills is available here:

Boston’s Complete Streets initiative:

MassDOT’s GreenDOT:

The Forest Hills Improvement Initiative is guiding development in the area

The Congress for the New Urbanism’s Highways to Boulevards project documents revitalized urban centers where overpasses and highways have come down:

Prepared by
Clayton Harper/ArborwayMatters
44 Hampstead Rd
Jamaica Plain, MA


October, 2013

To download a pdf of this briefing: