CSX Transportation resumed operations through the Howard Street Tunnel, paving the way for double-stack container service to and from Baltimore by mid-2026, reports New York's Journal of Commerce.

The US$500 million upgrade still requires bridge work before full double-stack operations can begin, but reopening the tunnel removes a key chokepoint that had disrupted freight flows since its closure on February 1.

CSX chief executive Joe Hinrichs said the tunnel unlocks new routing options from the Southeast to the Northeast and Chicago, adding that double-stacking could generate 75,000 to 125,000 new container moves annually.

The tunnel closure had effectively split CSX's east coast network in two, forcing containers to be trucked across Baltimore between terminals. The reopening is expected to cut transit by 24 hours.

The project also marks the end of a four-year effort to raise the tunnel's vertical clearance, originally built in the 1890s.