Simplified Green Line Extension plan approved by MassDOT, MBTA FMCB

Written by Mischa Wanek-Libman, editor
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The planned Massachusetts Bay Transportation Authority (MBTA) Green Line Extension (GLX) has been approved to proceed in a simplified version following months of project re-evaluation.

 

The Massachusetts Department of Transportation (MassDOT) Board and MBTA Fiscal and Management Control Board (FMCB) approved a motion to advance the Green Line Extension project at its May 9, 2016 meeting and the boards will now seek Federal Transit Administration review and approval.

The GLX project was hampered by major cost overruns, prompting the MBTA FMCB and MassDOT to adopt a resolution in December 2015 halting progress on the project until a series of conditions could be resolved under which the project could proceed.

MassDOT and MBTA FMCB created a multidisciplinary Interim Project Management Team (IPMT) tasked with addressing several key issues, including:

  • The ability for the project to be redesigned to reduce anticipated cost while maintaining its core functionality and benefits;
  • Methodologies to assure the project could be reprocured to reduce construction costs, increase cost reliability, and limit risks borne by the MBTA and MassDOT;
  • Best estimates of a realistic, revised project cost and schedule; and
  • Assurances that the provisions of the federal Full Funding Grant Agreement (FFGA) would not be adversely impacted as a result of the redesign.

 

The IPMT’s report to MassDOT and MBTA FMCB said, “The redesigned GLX project includes revisions to the stations, the vehicle maintenance facility, the viaducts and bridges, power and signal systems and the Community Path. The redesigned project is believed to be in conformity with the FFGA, as well as the federal Environmental Assessment and state Environmental Impact Report requirements and includes all stations on the Medford and Union Square branches. The station locations, platform size and functionality remain unchanged under the redesign program.

“In addition to significantly reducing project costs and schedule, the new and simplified project design presents fewer construction risks going forward.”

The biggest change for the project was the cost estimate. Previous estimates has put the GLX cost at $2.738 billion in contrast, the FFGA has available funds for a $1.992-billion project. The simplified version has estimates costs to be between $2.231 and $2.88 billion.

The majority of the cost savings comes from reduced station estimates (down 70 percent), bridge costs (down more than 40 percent), retaining walls and Community Path (down more than 65 percent), maintenance facility (down 59 percent) and a six-percent reduction in other project elements.

To simplify station designs without eliminating any of the stations themselves, designs eliminated elevators, escalators, fare gates, personnel rooms, toilets, extra structure for The RIDE drop-offs and canopies. For stations with large access grade separations (Gilman and Lowell) the redesign includes an elevator and access stairs. For the stations at Lechmere and College Avenue, the design includes redundant elevators (due to the large elevation differential between the street and the platform level), toilets and accommodations for MBTA personnel.

The previous design required modifications or replacement of the College Avenue, Broadway, Lowell Street, Washington Street, Medford Street and School Street bridges. The redesign scales back much of that work while retaining functionality for the project.

Additionally, the planned Community Path has been reduced in length by 3,000 feet or more than half a mile and street access points have been reduced from nine to four with a possible fifth.

Another large area of cost savings came from the maintenance facility, which will have a 55,000-square-foot maintenance building, which was reduced from 94,000 square feet, outside storage for 44 vehicles, a modular transportation building of 1,200 square feet, surface level parking, four service tracks, a seven-ton and a 10-ton crane, which was modified from the original plan that called for two five-ton crane and one seven-ton crane, and two inspection bays, which was reduced from four bays for service and inspection. All other features, such as a wash bay and extra storage, have been deleted, but certain foundation and structural elements have been sized for potential future expansion of the facility should funding become available.

The construction time line remains about the same. The original plan estimated the project to take 64 months where the simplified version budgets 18 month for procurement and 43 months for construction with the possibility for four additional months of construction should more than necessary winter work occur.

While the FTA still needs to approve the new plan, funding may be the project’s biggest hurdle as the revised cost estimate is still more than 10 percent over the funding currently available. Last week, in a bid to save the project, the Massachusetts municipalities of Cambridge and Somerville committed an additional $75 million for the project.

The full report from the IPMT is available below with details about all revisions made in the new GLX plan.

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