The mounting support, highlighted in recent filings with the Surface Transportation Board, includes 23 new corporate shippers and over 150 letters from community leaders and first responders. Proponents argue that replacing current fragmented routes with a single-line, transcontinental network will eliminate interchange delays, simplify billing, and improve overall reliability. Executives from companies such as POET Biofuels and Hub Group suggest that the integration would allow them to shift more freight from highways to rail, enhancing competitiveness while boosting market access.

The railroads estimate the merger could generate $3.5 billion in annual savings and divert 2.1 million truckloads from the nation's highways each year. Kenny Rocker, executive vice president at Union Pacific, stated that the backing reflects a shared industry belief in the value of seamless service. While the companies anticipate the deal will close in late 2027, the transaction remains subject to ongoing federal regulatory review and oversight by the Surface Transportation Board.