Union Pacific Escalates Feud With CPKC Over Southern Rail Corridor as Merger Politics Intensify

Railroad giant asks STB to investigate rival's handling of intermodal trains on the Meridian Speedway — a 300-mile flashpoint where merger ambition meets operational reality

Union Pacific is pressing federal regulators to open a formal investigation into Canadian Pacific Kansas City's handling of intermodal freight on the Meridian Speedway, a 302-mile joint rail corridor between Shreveport, Louisiana and Meridian, Mississippi that has become one of the most consequential chokepoints in American freight rail.

The dispute centres on train length. Before CPKC's 2023 acquisition of Kansas City Southern, UP routinely handed 11,000-foot double-stack container trains to KCS at Shreveport, which forwarded them east to Norfolk Southern at Meridian for the final leg to Atlanta. It was a well-oiled interline operation connecting the West Coast to the Southeast.

That arrangement has deteriorated. CPKC reimposed an 8,500-foot train length restriction on the Speedway last November, arguing that UP's overlength trains were blocking passing sidings and delaying every other movement on the corridor. Only three of the Speedway's sidings can accommodate trains longer than 8,500 feet, with gaps between them stretching up to 109 miles. UP now has to cut its trains in two at Shreveport before they can proceed — a process that adds hours of dwell time and, UP claims, has caused significant delays for shippers.

CPKC is not buying the victimhood narrative. In a blistering response to the STB, the railroad accused UP of trying to weaponise the regulatory process to force operational concessions on infrastructure that was never built to handle 11,000-foot trains. CPKC says its trains consistently depart ahead of schedule and that the added dwell time is entirely a consequence of UP's own decision to run overlength consists to Shreveport for its own convenience.

The stakes go well beyond a siding-length quarrel. Norfolk Southern estimates it has lost 100,000 intermodal loads through the Meridian gateway since 2022, with most of that freight returning to the highway rather than shifting to alternative rail routes. NS says CPKC promised regulators during the KCS merger review that it would maintain service levels at existing gateways — a commitment NS claims has not been honoured. CPKC counters that the volume decline reflects broader market headwinds including low trucking rates, a persistent freight downturn and UP's own decision to reroute certain intermodal flows.

The subtext is impossible to miss. UP is simultaneously asking the STB to approve its $85 billion merger with Norfolk Southern, arguing that interline agreements between competing railroads are inherently inferior to single-line service. The Meridian Speedway dispute is exhibit A in that case — a real-time demonstration, from UP's perspective, of why consolidation is the only reliable path to efficient coast-to-coast freight movement. CPKC, naturally, sees it differently: a rival manufacturing a regulatory grievance to bolster its merger pitch.

With the STB weighing both matters — the Meridian investigation request and UP's revised merger application due April 30 — the two proceedings are becoming increasingly difficult to separate. The outcome of each will shape the other.