Amtrak has selected HNTB for architectural and engineering services on the full replacement of the Bush River and Gunpowder River bridges, two 113-year-old structures on the Northeast Corridor between Baltimore and Wilmington, Delaware, with preliminary engineering scheduled to conclude in 2029.

The pair sits on a critical segment of the corridor. Together they carry more than 100 Amtrak, MARC (Maryland Area Regional Commuter) and freight trains daily, including Norfolk Southern. The scope covers 10 miles of right-of-way (the railway's land corridor). The work includes track realignment, modernized signaling and upgraded overhead catenary (the contact wire system that powers electric locomotives).

Why are these bridges being replaced now?

Age and deterioration have pushed both structures into a state-of-good-repair backlog (the maintenance deficit that occurs when infrastructure outlives its intended service life). Current speed limits sit at 125 mph. Mechanical failures have grown frequent.

In 2019, Bush River Bridge alone caused more than 72 hours of delay for Amtrak and MARC trains.

The movable Bush River span (a rotating or lifting section that allows marine traffic through) needs a 20-person crew during summer weekends to open for vessels on the Bush River. That is labor Amtrak will not have to repeat once the bridge is fixed.

What does the new design change for operations?

Higher speeds. Bush River Bridge will support 160 mph and Gunpowder River Bridge 145 mph, against 125 mph today. Modern signaling and added crossovers (switches connecting parallel tracks) on the 10-mile segment should expand capacity, letting Amtrak and MARC add service as Northeast ridership grows.

A fixed-span Bush River Bridge will better serve marine traffic and eliminate the 20-person opening crew. That changes a recurring summer operating cost into permanent steel.

"Today marks a critical step in the long journey to replace both the Bush River and Gunpowder River Bridges, key to improving the travel experience as record Amtrak ridership is projected to continue growing over the next decade," said Laura Mason, Amtrak Capital Delivery executive vice president.

Who is funding the current phase?

Preliminary engineering and NEPA review (the federal environmental assessment process required for major federally funded projects) draw primarily on a Federal Railroad Administration grant, with Amtrak and the Maryland Transit Administration covering the balance. Both bridges sit on the FRA's NEC project inventory as key priorities. Final design and construction funding remain to be identified.

What is HNTB's prior role on the corridor?

HNTB has supported Amtrak on several Northeast Corridor bridge programs, including the ongoing Susquehanna River Bridge replacement in Maryland and the Portal North Bridge program in New Jersey. Amtrak and NJ Transit opened the first track on Portal North earlier this year; the second and final track is scheduled to open this fall.

"These projects represent an important opportunity to continue our longstanding partnership with Amtrak on infrastructure that is essential to the Northeast Corridor," said Christian Brown, HNTB project manager.

Where the bridges sit

Gunpowder River Bridge, completed in 1913, runs between Chase and Joppatowne, Maryland. Bush River Bridge, also 1913, lies to the north between Edgewood and Perryman. Past failures to close have stranded Amtrak services between New York, Philadelphia and Washington.

The wider corridor program

Amtrak is advancing other major bridge programs in parallel. A $133 million Federal-State Partnership grant funds enabling components for the Sawtooth Bridges replacement, serving more than 200,000 daily customers. Rehabilitation of Dock Bridge in New Jersey is set to begin after this summer's contract awards.

The Maryland pair now enters design with engineering due in 2029 and construction dollars still to be secured. Delivery falls in the second half of the decade at the earliest.