The original six-lane highway, built in 1959 on an elevated structure, was plagued by tight turns, an excessive number of exits, entrance ramps without merge lanes, and continually escalating traffic. The Central Artery project was developed in response to these challenges. Construction started in 1991 and by 1995, the Ted Williams Tunnel and the Storrow Drive Connector Bridge were finished. In 2003, the extension of I-90 to Logan Airport via the Ted Williams Tunnel was completed. By 2005, all lanes in the new Central Artery Tunnel were opened to traffic.
Project Type:Limited Access Road Project Mode:Highway Average Annual Daily Traffic:154,000 Length (mi):7.80
Economic Distress:0.89 Population Density (ppl/sq mi):12135 Population Growth Rate (%):0.14
Employment Growth Rate (%):-0.38 Market Size:1,748,525 Airport Travel Distance:13.35 Topography:4
Region:New England/Mid-Atlantic State:MA County:County
City:Boston Urban/Class Level:Metro Local Area:N/A
Impact Area:County Transportation System:N/A GIS Lat/Long:42.358145 / -71.051921
Initial Study Date:N/A Post Constr. Study Date:2006
Constr. Start Date:1991 Constr. End Date:2006
Project Year of Expenditure (YOE): N/A Planned Cost (YOE $):5,600,000,000
Actual Cost (YOE $):14,800,000,000 Actual Cost (curr $):17,712,531,406
NOTE: All pre/post dollar values are in 2013$
Select a region to display the conditions for that region:
NOTE: All impact dollar values are in 2013$
|Income (in $M's)||4053890000.00||2229640000.00||6283530000.00|
|Output (in $M's)||8988550000.00||4943700000.00||13932250000.00|
The $14.7 million Central Artery project removed the elevated portion of I-93 that passed through downtown Boston's waterfront district and replaced it with a tunnel. The Rose Kennedy Greenway now lines a 1.7 mile long corridor within downtown Boston that was once blighted by what locals called ?the Green Monster.? In order to alleviate bottlenecks that were crippling Boston's growth, connections to the new tunnel received a significant capacity expansion with the construction of the I-90 Ted Williams Tunnel to the airport and the new Storrow Drive connector to Beacon Hill. The infusion of nearly $15 billion in the project has bolstered investment confidence in the future of downtown which is rapidly expanding, both vertically and horizontally. An estimated 100,000 jobs are expected to be created in development projects sparked by the project. About 50,000 of these jobs are expected to be directly attributable to the Central Artery Project.
2.1 Location & Transportation Connections
High speed connections for the I-93 new tunnel were a major part of the project. New connections to the Central Artery Tunnel built as part of the project include:
* Zakim Bunker Hill Memorial Bridge connecting to I-93 * Storrow Drive Connector Bridge providing access to the west * The extension of the Massachusetts Turnpike to Logan Airport including: o The 1.6 mile Ted Williams Tunnel under Boston Harbor connecting I-90 and I-93 with Logan Airport. o The Silver Line Tunnel under the Fort Point Channel which serves a new bus rapid transit line connecting downtown to the airport
These new high-speed connections replaced traffic bottlenecks on local streets previously used to access the elevated Central Artery. After construction of the Central Artery Tunnel was completed, the old elevated structure was demolished and the surface area released was restored as an urban park with a limited number of new development sites.
2.2 Community Character & Project Context
The city of Boston, with just over 600,000 people is an important center of education, healthcare, financial services, and government. Its rich history attracts over 16 million tourists a year. The Central Artery Project replaced a 1.7 mile stretch of highway in the heart of downtown that cut off the city's waterfront with a tunneled freeway. This corridor is lined by some of the city's principle tourist attractions -- Faneuil Hall, Rowe's Wharf, New England Aquarium, the Children's Museum, and the North End. A linear park now unites these neighborhoods, which were previously severed by the unsightly green elevated highway that was replaced by the Central Artery tunnel. This has supported both commercial and residential development downtown.
The original elevated Central Artery project was developed in response to traffic congestion on Boston's historically tangled streets, which were laid out long before the automobile. The ?highway in the sky? was originally opened in 1959. The six-lane highway, built on an elevated structure through the heart of downtown, had six lanes that were designed to accommodate 75,000 vehicles a day. The road was built before strict highway safety standards were adopted, and the expressway was plagued by tight turns, an excessive number of exits, entrance ramps without merge lanes, and continually escalating traffic.
In the early 1970's, public opposition had killed a proposed inner-belt highway that would have served as a bypass for the Central Artery. A moratorium on new highway construction within the city of Boston was imposed. The lack of a bypass for the Central Artery put ever-increasing traffic volumes onto I-93. Severe traffic congestion caused inefficiencies that threatened to choke the future economic growth of the city.
Planning for the Big Dig began in 1982. Despite stiff opposition from President Reagan, the project won federal funding in 1987. Construction started in 1991 and by 1995, the Ted Williams Tunnel and the Storrow Drive Connector Bridge were finished. In 2003, the extension of I-90 to Logan Airport via the Ted Williams Tunnel was completed. By 2005, all lanes in the new Central Artery Tunnel were opened to traffic. Restoration of the Artery surface then began. The Rose Kennedy Greenway, a linear park on the restored highway surface opened in 2007.
The cost of the Central Artery Project was originally estimated at $2.8 billion in 1985. It continued to escalate throughout the design and construction phases. In 2002, three years before the project was completed, costs were quoted at $14.8 billion, making it the most expensive public works project ever undertaken. The official cost is still quoted at $14.8 billion (2002$). There is speculation, however, that the actual final project costs of the project, on which contracts are still out, could range up to $20 billion. Initial funding for the project was to be 90% federal and 10% from state sources. But in response to escalating costs, the federal government capped its contribution at $8.45 billion in 2001. The final allocation of costs between state and federal levels has not yet been calculated.
Aesthetically, the elevated highway structure was always unpopular with Bostonians. Standstill traffic made the rusting structure look like an elevated parking lot at peak times. Surrounding neighborhoods were blighted by noise, pollution, and shadows. Neighborhood residents began to demand the removal of this polluting ?green monster?, as the structure was called, and a reunification of city neighborhoods, providing strong public support for the project.
4.1 Transportation Impacts
The elevated Central Artery was originally built to carry 75,000 vehicles a day, but by the 1990's traffic volumes had grown to nearly 200,000 a day. Traffic jams of 16 hours were predicted for 2010. A major reason for the congestion is that the Central Artery carried not only north-south traffic, but also channeled east-west traffic between I-90 and Logan Airport. By providing a new airport tunnel with direct connections to I-90 via the new Fort Point Tunnel, a new Storrow Drive connector bridge, and a new bridge over the Charles River to connect with I-93, the Big Dig untangled traffic in Central Boston. While only one additional lane in each direction was added to the north-south I-93 in the new tunnel, the new east-west connectors reduced traffic demands on the Central Artery significantly.
The result was a 62% reduction in vehicle hours of travel on I-93, the airport tunnels, and the connection from Storrow Drive, from an average of 39,200 hours per day before construction in 1995, to 14,800 hours per day in 2004, when the project was largely complete. Meanwhile, total daily traffic volume grew by 25% on this route. The savings for travelers is estimated at $168 million annually. Peak travel times on the 1.7 mile Central Artery northbound were reduced by 85%, from 20 minutes to 3 minutes. Southbound peak travel time was cut by 67%.
A number of public transit projects were part of the environmental mitigation package. The most extensive was the construction of Phases II of the Silver Line, a bus rapid transit line running in a new tunnel built under the Fort Point Channel, which was built as part of the mitigation package. The Silver Line Tunnel provides a direct link between South Station and the airport terminals. Extensions of and new connections for the Green, Red, and Blue subway lines are also underway.
The Central Artery project has supported Boston Harbor water transportation services for both passengers and freight. A new ferry terminal has been built at North Station. Docking facilities have been improved at the World Trade Center, Long Wharf, the Charlestown Navy Yard, and on Spectacle Island. Subsidies for inner harbor water transportation have been upgraded. An intermodal cargo facility is now under construction at the Cargo Terminal in the Seaport District, a major development area which was made accessible by the Central Artery Project.
4.2 Demographic, Economic & Land Use Impacts
The heavy investment of planning and financial resources that went into traffic re-routing during construction of the Central Artery project kept business booming in downtown Boston during the long construction period. During the 16 year period before the Central Artery was constructed, Boston lost 8% of its population, while Eastern Massachusetts (Norfolk, Middlesex, and Essex counties) registered a sluggish l.9% growth in residents. Jobs in Boston grew by 13% from 1974 to 1990, while those in the surrounding counties grew three times as fast.
From 1990 to 2006, partly as a result of the new downtown condominiums built in response to the project, Boston reversed the trend of population loss, gaining back most of the residents that it had lost during the 1970's and 1980's. Boston's population growth rate exceeded that of the surrounding suburban counties. The new population attracted was more affluent than that of surrounding towns.
Demolition of the elevated highway structure has reduced pollution and noise and has created 27 acres of new open space that now defines the Central Artery Corridor. Three-quarters of this space has been devoted to public parks and surface roads, leaving just seven acres on the former interstate right-of-way for private development. The area that was occupied by the elevated structure has become the Rose Kennedy Greenway, a linear park that now unites the downtown neighborhoods that were previously severed by highway. Throughout the city, over 300 acres of landscaped open space have been created as part of the mitigation package, including 45 parks and public plazas. The Charles River Basin, Fort Point Channel, Rumney Marsh, and Spectacle Island have all received major shoreline restoration.
A 2004 report found that, in the fifteen years that spanned the Central Artery construction the value of commercial properties along the Rose Kennedy Greenway increased by 80% -- nearly double the city-wide average increase. Since three-quarters of the 27-acre area released by removal of the highway was required for open space, only a limited number of new sites for private development were available. Due to prevailing real estate market conditions over the past several years, most of these sites are being developed for high-end condominiums and apartments overlooking the Greenway.
Although a limited number of new development sites were released by the project, the confidence inspired by this massive public investment and by the access and environmental improvements that it wrought, strengthened the downtown property market significantly. It has sparked new interest in planning for air rights development in the wider Central Artery Corridor, which has been defined as the area with a half-mile radius of the project.
The I-90 extension of the Mass Pike to the airport, via the new Ted Williams and the Fort Point Channel Tunnels added a new interchange in South Boston which has made the Seaport area accessible to the region, opening this 1000-acre area for redevelopment. The Silver Line, completed as part of the mitigation package, links the Seaport District with South Station and with Logan Airport. A new live-and-work community is being developed here with over 15 million square feet of new and planned commercial and residential space.
Development of the Seaport District has been anchored by the strategic siting of a several new high-profile public buildings there including the $75 million Institute of Contemporary Art and the $170 million award-winning Moakley US Courthouse, designed by I.M. Pei. The $800 million Boston Convention and Exhibition Center, completed in 2004, is attracting new hotels, retail, restaurants, and entertainment to the district.
The comprehensive redevelopment of the Seaport area in South Boston as an extension of downtown would not have occurred without the projects. New road and transit links to this previously-isolated but well-located area on Boston's waterfront just south of downtown have enabled the assembly of large sites for redevelopment that are unavailable elsewhere in the central city. This could house up to 58,000 new jobs with personal and business income of $2.2 billion per year and new hotel tax revenue of $1 billion annually.
Based on these estimates and on the projections of development currently underway and planned, and the review of the overall performance of the Suffolk County economy, the economic impacts of recent and planned development projects enabled by the Central Artery project are forecast to be 50,000 jobs in 25 million square feet of new development representing an estimated investment of $6.3 billion.
In total (including future development plans), 98 projects that will add over 50 million square feet of floor space in downtown Boston have been put forward, principally for development of air rights parcels. In total, nearly 100,000 new jobs are expected to be created on these sites, principally as a result of new office space. In view of sluggish economic and real estate market conditions, the build out period for this development could be a decade or more.
Numerous demographic, economic, regulatory, and political factors influenced the growth of investment in downtown Boston while the Central Artery was under construction. These include the growth of the financial services sector, Boston's high quality workforce, the trend toward chic city living, and the real estate bubble that marked the late 1990's and the early years of the Millennium. These factors were harnessed by a clear vision and astute planning on the part of the Boston Redevelopment Authority, the Massachusetts Turnpike Authority, the MBTA, and MassPort.
Some of the development is likely to have occurred if the Central Artery project was not undertaken. But much of the new development activity in the Financial District, the North End, and the West End was stimulated by the improved access, environment, and bullish investment climate created by the Central Artery Project.
Alan Altschuler & David Luberoff, Mega Projects: The Changing Political of Urban Public Investment, 2003.
Economic Development Research Group, Transportation Impacts of the Massachusetts Turnpike Authority and the Central Artery/Third Harbor Tunnel Project, Volume I. Feb 2006
Economic Development Research Group, Real Estate Impacts of the Massachusetts Turnpike Authority and the Central Artery/Third Harbor Tunnel Project, Volume II, Feb 2006
Goody Clancy Associates, A Civic Vision for Turnpike Air Rights in Boston, 2000
Thomas Palmer, For Property Owners, Parks Mean Profits, Boston Globe, June 14, 2004.
New York Times, ?From Empty Lots to Bustling Waterfront,? Oct. 7, 2007
OrganizationMassachusetts Turnpike Authority A Better City (formerly) Artery Business Committee Boston Redevelopment Agency