The U.S. Surface Transportation Board announced on Aug. 18 that the earliest it would make a final decision on Union Pacific’s proposed acquisition of Norfolk Southern would be the second half of 2027. The board ruling came less than a month after UP and NS filed additional information with the federal regulator that will either approve or deny the largest railroad merger ever proposed in American history.

According to the timeline issued by the STB, those interested in participating in the review would have to state their intent by September 4. That would kick off a series of deadlines for comment, including from the Department of Justice and Department of Transportation. By March of next year, rebuttals would be due from all parties, and at some point after that a public hearing would be held. Final briefs on the proposed merger would be due on May 28, 2027. At some point after that, the record would close, and the STB would have 90 days to issue a final ruling, meaning it would likely be late summer 2027 at the earliest. The decision would not be issued, however, if the required environmental review were not complete yet.

If approved, the combined UP-NS would stretch more than 50,000 miles and touch 43 states. The merger was first proposed in mid-2025, but the STB rejected UP’s first application as “incomplete.”

—Justin Franz