Two studies put the cost of building a passenger rail link between Austin and San Antonio at $13 billion — unless planners choose a route that Union Pacific has already resisted, Texas Public Radio reports.

The figure anchors a new chapter in one of Texas's longest-running passenger rail debates: how to connect two metropolitan areas that together hold several million residents along the Interstate 35 corridor.

What do the studies actually say?

The studies, reported by Texas Public Radio, frame the project's core trade-off as financial versus institutional:

• A build option priced at roughly $13 billion; or
• An alignment that avoids much of that capital cost but relies on right-of-way or routing cooperation from Union Pacific — cooperation the Class I railroad has resisted.

That resistance is the practical obstacle. Freight railroads in the United States routinely decline to host scheduled passenger service on busy freight corridors, citing capacity, liability and dispatching concerns. Any Austin–San Antonio service that uses existing UP infrastructure would need to overcome exactly those objections before a single train runs.

Why the corridor keeps resurfacing

Austin and San Antonio sit roughly 80 miles apart along I-35, one of the most congested highway corridors in Texas. State and regional planners have studied passenger rail between the cities repeatedly over the past two decades without reaching construction.

The $13 billion estimate gives decision-makers the most concrete pricing signal the project has had. Whether that number changes the political arithmetic — or pushes planners back toward the contested routing — is now the central question.

What happens next?

The studies' findings will feed into regional transportation planning, where officials must decide whether to pursue funding for the full-cost option or reopen negotiations over the alignment Union Pacific has resisted.