As freight demand continues to rise, the ability to efficiently move goods by rail is more important than ever. For leading Class I freight railroad CSX Transportation (CSX), that means eliminating vertical clearance barriers that have long limited the railroad’s capacity to transport double-stacked containers between key markets along the East Coast. Double-stack service allows CSX to move twice as much freight with the same locomotive power – delivering significant fuel and cost savings while improving the overall efficiency of the network.
To alleviate existing constraints, the $500 million Howard Street Tunnel Clearance Program is an ambitious freight corridor improvement initiative intended to bring double-stacked container service to the Port of Baltimore, with clearance projects along the nearly 100-mile corridor between Baltimore and Philadelphia. One of the most critical bottlenecks along this route is the 130-year-old Howard Street Tunnel which runs directly beneath downtown Baltimore.
While the Howard Street Tunnel represents the centerpiece of the program, it’s just one part of a much larger effort. In total, the program includes 22 locations across Maryland, Delaware and Pennsylvania where vertical clearances will be increased by up to 18 inches. Grouped into 10 construction packages, these improvements are unlocking new freight capacity through this vital corridor.
STV has been working alongside CSX and other partners since December 2021, providing comprehensive program management and construction management (PM/CM) services for all 10 construction packages. The program draws on a broad range of STV’s expertise – from our long-standing track record of designing and managing capital projects that enhance freight mobility along some of the nation’s busiest freight corridors, to the capabilities of our growing geotechnical, underground structures and tunneling practice.
As of this spring, all 22 sites have entered the construction phase – with several already complete – marking a major turning point in the program as progress is accelerating across the board.
Progress to Date
Last October, the program reached its first major construction milestone, when CSX launched double-stacked rail service portion for trains entering the northern of the Port of Baltimore, which was made possible by vertical clearance improvements that were completed north of the Howard Street Tunnel. Namely, four construction packages were completed in the program’s Bayview North (BVN) section, which primarily involved lowering tracks. This milestone marked the first segment of the corridor to reach full double-stack operational readiness.
Meanwhile, work has continued in the Bayview South (BVS) portion of the corridor. The goal within this section is enabling double-stack access into the southern portion of the Port of Baltimore, which requires major infrastructure upgrades in Baltimore City itself. This includes three critical bridge replacements and modifications at Harford Road, Guilford Avenue and North Avenue, as well as the reconstruction of the Howard Street Tunnel itself – the most high-profile component of the entire program.
The Tunnel at the Center
Originally constructed in 1895, the Howard Street Tunnel has long been the primary obstacle to double-stack rail service into the southern portion of the Port of Baltimore. In early February, the tunnel was fully closed to rail traffic to allow construction crews to begin interior reconstruction. The team reached a key milestone with the removal of the first set of rail spikes, officially kicking off one of the most significant and technically complex phases of the entire program. This phase represents the most intensive stretch of construction yet and requires the largest STV staffing presence on the program to date.
Reconstructing a 1.7-mile tunnel under a dense urban environment is no small feat. We’re coordinating work around constrained spaces, active infrastructure and a wide range of technical and environmental challenges. Over the next several months, our team will oversee new track installation, tunnel lining repairs, improved drainage and structural modifications to achieve the necessary 18-inch vertical clearance.
Once tunnel work wraps up at the end of 2025, CSX will achieve full double-stack clearance through the tunnel. The remaining construction efforts, including final bridge and access improvements, will follow soon after. By mid-2026, double-stacked rail service will be fully operational into both the northern and southern portions of the Port of Baltimore.
A Transformational Impact
When fully complete, the Howard Street Tunnel Clearance Program will allow CSX to operate double-stacked container trains along the entire East Coast – from Maine to Florida. This will reduce transportation costs, increase freight capacity and offer environmental benefits by shifting more cargo from road to rail.
For the Port of Baltimore, this program is expected to drive major growth: increasing throughput by an estimated 160,000 containers annually and generating more than 13,000 construction and operations jobs across the Baltimore region.
For our STV team, it’s incredibly rewarding to help bring this program to life – from on-the-ground inspections to strategic coordination with CSX, the Federal Railroad Administration and our state partners. We’re proud of what our team has accomplished so far and excited to see the full impact of this program unfold in the years ahead.
