green line extension glx update presented to the board on
TRANSCRIPT
Green Line Extension Project Update
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Green Line Extension UpdateFiscal and Management Control BoardJohn Dalton, Program ManagerApril 13, 2020
Green Line Extension Project Update
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Agenda
• GLX Project Update• GLT Lechmere Viaduct Rehabilitation (B22CN02) & Coordination with
GLX• Lechmere Station Closure and Bus Diversion
Green Line Extension Project Update
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Design Build Entity Contract Cash Flow & Spending
Updated Quarterly. Revised as of December 31, 2019.Actuals = Paid only (does not include retainage or change orders)
Green Line Extension Project Update
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Gilman Square
Lechmere Viaduct and Station Area (existing and
future)
Green Line Extension Project Update
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Red Bridge Viaduct Area
(looking north)
Green Line Extension Project Update
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Future East Somerville
Station
Green Line Extension Project Update
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Broadway Bridge Steel
Erection
Green Line Extension Project Update
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Broadway Bridge Steel
Erection
Green Line Extension Project Update
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Future Union Square Station
Green Line Extension Project Update
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GLX Site Overview
Project Coordination Area
Green Line Extension Project Update
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Lechmere Station Demolition & New Viaduct Section
Historic Concrete Viaduct Rehabilitation
by GLT
Demolition of Existing Steel Viaduct – Spring
2020
Green Line Extension Project Update
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Lechmere Project Limits
GLX – Project Limits GLT – Lechmere Viaduct Rehabilitation Project
Green Line Extension (GLX) Green Line Transformation (GLT)
Green Line Extension Project Update
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Charles River Dam RdEd
win H
Land
Blvd GLT: Lechmere Viaduct
Rehabilitation Project
Gilm
ore B
ridge
Physical Conditions• The existing railing, deck, and stringer
conditions warrant replacement due to extensive chloride intrusion and map cracking of the concrete
• Additional concrete and steel repairs necessary to extend the life of the structure
Strength Requirements• The structure’s current load rating indicates
the concrete arches are below statutory requirements, restricting the number of simultaneous revenue vehicles and work cars on the viaduct
GLT Lechmere Viaduct Rehabilitation Project
Science Park/West End Station
Concurrent with GLX: Lechmere Station Demolition & Relocation
GLX Project Limit
Green Line Extension Project Update
• Existing Service Maintained: Bus Routes 69, 80, 87, and 88 continue to connect Somerville, Cambridge, Arlington, and Medford to Lechmere
• Green Line Shuttle: A separate fleet of accessible shuttle buses will connect Lechmere to North Station to meet or exceed existing Green Line headways
• Station Bus Infrastructure: Existing Bus Garage and Operator Facilities to remain until new bus loop and new Lechmere Station are fully functional
Lechmere Station Operations
Lechmere Bus Replacement Service
Bus Replacement Service expected to start on or around May 25th
Green Line Extension Project Update
• Conversion to all-day two-way bus lanes, and accompanying bus lanes conversion in Cambridge and Boston
Charles River Dam Road (Craigie Dam)
Existing
Conversion with bus lanes
Lechmere Bus Replacement Service
Green Line Extension Project Update
Bus lanes are needed to maintain people capacity
• In the absence of buses, many of the 14,000+ Green Line riders may choose to drive and overload the roadway system
• Congestion may increase with or without bus lane, but bus lane guarantees a reliable transit alternative
• Bus Lanes also projected to save up to 15 minutes round-trip per passenger during weekday peak travel times
Lechmere Bus Replacement Service