The Massachusetts Bay Transportation Authority’s (MBTA) $1.286 billion North Station Draw One Bridge Replacement Project represents one of the most significant rail infrastructure investments in Massachusetts history and a transformative effort to eliminate one of the most important rail gateways in New England’s passenger rail network. A ceremonial groundbreaking in September brought state leaders, transportation officials and project partners together to officially launch construction of the long-anticipated program.
For STV, the milestone represents the latest chapter in a years-long effort that has ranged from planning and engineering the complex bridge replacement to securing the largest federal grant award in MBTA history, a critical step that moved the project from concept to construction.
The project will replace the existing Draw One Bridge, a pair of movable rail spans crossing the Charles River into North Station, with a modern six-track river crossing designed to improve reliability, increase network capacity and support future growth in the corridor. Serving MBTA’s Haverhill, Lowell, Newburyport/Rockport and Fitchburg lines, as well as Amtrak’s Downeaster service, the bridge is one of the most important rail chokepoints in New England.
STV’s involvement stretches back to the project’s earliest stages. Since 2019, the firm has served as the MBTA’s lead consultant, providing planning studies, preliminary and intermediate design phase services for the replacement program. STV’s multidisciplinary team has led bridge, civil, structural, mechanical and electrical engineering efforts while also overseeing track and signal design, environmental approvals, permitting, stakeholder coordination and public outreach.
In early 2025, MBTA committed to use design-build as the procurement method for project completion. The STV Team has supported the MBTA in developing and finalizing the design-build procurement documents and has provided support throughout the procurement process. This effort has included review and evaluation of Alternative Technical Concepts and review of technical proposals. With the design-build team now receiving a notice to proceed, STV is providing design review and other support services for the MBTA.
The project centers on infrastructure that has outlived its original design life. Constructed in 1931, the existing Scherzer rolling lift spans carry four tracks across the Charles River and support more than 200 MBTA and Amtrak train movements on a typical weekday. Decades of service, exposure to the elements and constant bridge openings for marine traffic have contributed to corrosion, structural deterioration and operational reliability issues.
The aging structure has become a bottleneck for rail operations north of Boston, limiting service flexibility and contributing to delays across the system. Those constraints can ripple throughout the regional rail network, affecting commuter and intercity passenger service that connects communities across northern Massachusetts, New Hampshire and Maine to Boston’s economic center.
“The Draw One Bridge sits at the heart of rail operations entering and leaving North Station, which makes replacing it an extraordinarily complex engineering challenge,” said Mark Ennis, PE, vice president and engineering chief at STV. “We’re designing and delivering a modern movable bridge system while maintaining active rail service for hundreds of train movements every week. That requires careful planning, innovative staging strategies and close coordination across multiple engineering disciplines.”
The solution developed by the project team replaces the two existing movable spans with two new three-track bridges, expanding the crossing from four tracks to six. The six tracks will help reduce congestion and improve how trains move through North Station while supporting future service reliability. The project also includes the replacement of approximately 500 feet of rail approach trestle structures, the replacement of the aging Signal Tower A facility, the installation of upgraded signal and communications systems, the installation of 80 new switches and 10 miles of new track, and the expansion of North Station from 10 tracks and five platforms to 12 tracks and six platforms.
One of the project’s defining challenges is maintaining service while rebuilding a bridge that serves as the sole rail gateway into North Station. Rather than shutting down the crossing, the construction program was designed to keep four tracks operational throughout construction. The plan calls for building a new 3-track bridge adjacent to the existing structure before replacing the original spans with a second new 3-track bridge, allowing trains to continue serving riders throughout the multi-year construction effort.
“Maintaining uninterrupted service was a fundamental requirement from the beginning,” said Marian Barth, vice president and Boston area manager for STV. “The challenge was creating a solution to modernize a vital gateway into North Station while preserving the reliability riders and operators depend on every day. Achieving that balance has required close coordination among the MBTA, project partners and experts across bridge, track, signals, environmental and construction disciplines to ensure the region can continue moving while this critical investment takes shape.”
That approach extended beyond engineering and design. In 2024, STV played a key role in helping the MBTA secure a historic $472 million Multimodal Project Discretionary Grant (MPDG) MEGA grant from the U.S. Department of Transportation, the largest federal grant award in MBTA history. STV’s infrastructure economics and grants advisory team provided technical assistance in developing the benefit-cost analysis that demonstrated the project’s value and supported the agency through post-submission requests for information.
The award represented a major milestone for the project and helped strengthen the financial foundation necessary to advance the bridge replacement into final procurement and construction.
While the new bridge will improve reliability and resilience, its impact extends across the broader rail network. Additional tracks and upgraded interlockings will give operators greater flexibility when routing trains into and out of North Station. The improvements will also enhance access to the MBTA’s Boston Engine Terminal, improve operational efficiency and enhance service across northern commuter rail corridors.
The project reflects STV’s long-standing presence in Greater Boston, where the firm has supported transportation infrastructure for more than four decades. From major bridge rehabilitation programs to rail expansions and transit improvements, STV has helped shape many of the systems that connect residents and visitors throughout the region.
As construction progresses toward its anticipated completion in 2032, the North Station Draw One Bridge Replacement Project will remain one of the most closely watched transportation investments in Massachusetts, not only because of its engineering complexity, but because of the role it will play in shaping the future performance of the region’s rail network for generations.
“This project demonstrates what can happen when long-term planning, innovative engineering and strategic funding come together around a clear vision,” Ennis said. “The result will be a more reliable, more flexible and more resilient rail network that supports the region for decades to come.”
