BALTIMORE, Md. — A joint venture between Sweden-based construction leader Skanska and Mid-Atlantic infrastructure firm Fay has completed the $450 million Howard Street Tunnel Modernization Project in Baltimore almost two years ahead of schedule, marking a major achievement in one of the region’s most important freight rail upgrades.
The project, undertaken for CSX Transportation, aimed to modernize the historic Howard Street Tunnel to accommodate double-stack freight trains, significantly improving freight capacity along the Baltimore-to-Philadelphia corridor and enhancing overall logistics efficiency across the Mid-Atlantic and Midwest rail network.
Originally expected to finish in August 2027, the project reached substantial completion in September 2025, according to a Sept. 30 press release from the companies. Remaining tasks include finalizing a detention pond and pump station startup at the tunnel’s west portal, according to Michael Goetz, project manager for Skanska.
“The progressive design-build approach created strong collaboration among the owner, contractor, and designer, enabling the team to balance priorities and construction methods,” said Goetz. “The schedule further improved when CSX green lit a continuous tunnel outage for construction.”
The progressive design-build model, which emphasizes transparency, collaboration, and flexibility, allowed the joint venture to adapt designs and optimize resources throughout construction. This approach, combined with 24/7 work shifts and a full tunnel shutdown, was key to completing the job nearly two years early.
“By maintaining open communication and iterative design adjustments, we were able to accelerate construction while maintaining safety and quality standards,” Goetz added.
The construction challenge was substantial. Crews had to raise the clearance of the 8,700-foot-long tunnel by two feet to accommodate double-stacked trains, all without damaging the original 1895 brick archway. Using a custom-built railcar-mounted gantry crane, workers demolished the existing floor, excavated below, and installed nearly 1,200 precast concrete invert slabs, each measuring roughly 18 to 19 feet across, to create the tunnel’s new base.
The progressive design-build method also provided opportunities to test and refine techniques in real time, enabling the project team to lower the tunnel floor safely while ensuring structural integrity.
The modernization of the Howard Street Tunnel is part of CSX’s broader capital improvement initiative, aimed at boosting freight movement efficiency across major Eastern U.S. corridors. Once fully operational, the upgraded route will reduce shipping bottlenecks, increase cargo throughput, and offer significant economic benefits to ports, logistics centers, and regional industries dependent on efficient freight rail service.
The collaboration between Skanska, Fay, and CSX demonstrates how innovative project delivery methods and strategic partnerships can dramatically improve outcomes on complex infrastructure projects.
Originally reported by Zachary Phillips in Construction Dive.
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