Union Pacific and Norfolk Southern are seeking to bolster their case for creating America’s first transcontinental railroad by adding what they describe as an unprecedented set of customer assurances as the Surface Transportation Board reviews their merger application.

The companies said the supplemental filing late Monday responds to STB requests for additional information and goes beyond protections offered in prior rail mergers.

The filing marks a shift in the merger argument, moving beyond broad strategic benefits and toward more concrete shipper protections. That distinction is significant in a review process where regulators will weigh not only competitive effects, but also service reliability, access to alternatives and whether promised benefits are likely to reach customers. It also reflects the broader challenge facing any large rail consolidation: even when companies argue that longer through-routes can reduce handoffs, regulators tend to focus on whether shippers will still have workable options if service or pricing disputes arise.

The filing is the second of two tranches and covers information requested by the STB when it conditionally approved the carriers’ second merger application in late May.

Four new commitments

The 400-plus-page filing adds or expands four commitments:

• Expanded committed pricing opportunities, including a larger Committed Gateway Pricing program and coverage for bulk unit train shippers.
• Broader customer protections that preserve Class I rail options for both 3-to-2 and 2-to-1 shippers where legally possible.
• Temporary access to alternative rail service if integration causes a service decline.
• A new rate relief process if the merger’s public benefits are not delivered in a timely manner.

Taken together, the commitments are intended to address the two most common objections in rail mergers: reduced competition and service disruption after integration. For customers that depend on rail for high-volume, time-sensitive, or hard-to-switch freight, the details matter because the practical value of any merger often comes down to whether pricing programs, routing choices and fallback service remain usable after the integration is complete.

Union Pacific (NYSE: UNP) said the measures were developed after listening to customers and reviewing the STB’s comments. Chief Executive Jim Vena said the combination would deliver faster, more reliable coast-to-coast service and savings that could flow through to consumers.

Competitive argument

Union Pacific and Norfolk Southern (NYSE: NSC) are also working to frame the deal as pro-competitive rather than consolidation for its own sake. Their public materials emphasize minimal route overlap, more direct routing, fewer handoffs and expanded access to ports and international gateways, with the merger intended to create a single line from the West Coast to the East Coast.

Another important element in the broader merger package is the effort to resolve terminal and gateway concerns. The companies said they have completed responses to the STB’s supplemental information requests, and a separate binding agreement with Canadian National (NYSE: CNI) is intended to settle ownership issues involving the Terminal Railroad Association of St. Louis and the Kansas City Terminal Railway.

The additions come as public opposition to the merger grows. In a July 24 letter to the STB, 24 senators urged the regulator to closely evaluate Union Pacific’s acquisition of Norfolk Southern. They warned of possible effects including higher consumer costs, as well as service and safety issues.

What to watch

The central question now is whether the STB views these voluntary commitments as sufficient to offset the structural concerns of a two-to-one transcontinental rail merger. The companies still expect closing in mid-2027 if the transaction is approved, but the path forward will depend heavily on whether regulators conclude the promised competition safeguards are durable and enforceable.

For shippers, the most relevant part of the filing is not the merger rhetoric but the practical promise of more routing options, temporary fallback service if problems arise and a rate relief mechanism if benefits lag. That suggests the railroads expect the regulatory fight to be decided on customer impact, not just strategic scale.