A proposed high-speed rail connection between Austin and San Antonio could cost approximately $13.5 billion to build, according to a recent feasibility study commissioned by Travis County.

The proposed project would connect Austin-Bergstrom International Airport with the Amtrak station in San Antonio. The route would generally follow State Highway 130 and Interstate 10 and could allow trains to travel at speeds of around 125 miles per hour.

If developed as proposed, the 89-mile journey could take about one hour, potentially providing an alternative to driving between the two rapidly growing Texas cities.

High-Speed Rail Faces Significant Construction Challenges

The feasibility study, conducted by HNTB Corporation, identified several infrastructure challenges along the proposed route.

One major issue is the limited space available within existing transportation corridors. The route contains numerous cross-street overpasses, while some existing rights-of-way provide little room for a new rail line.

As a result, a significant portion of the proposed high-speed rail system would need to be elevated. These construction requirements contribute substantially to the estimated $13.5 billion project cost.

Beyond construction, the system would also require ongoing funding. The study estimates that operating and maintaining the high-speed rail line could cost approximately $190 million annually.

The feasibility study did not provide estimates for potential passenger numbers or ticket fares.

Why Passenger Rail Is Being Considered

Supporters of expanded passenger rail point to continued population growth in the Austin-San Antonio region.

The broader area connecting Travis and Bexar counties is already home to millions of residents, and continued growth could place additional pressure on Interstate 35 and other major highways. Similar investments in transportation and regional infrastructure are also taking place in other rapidly growing parts of Texas, including Houston and The Woodlands.

Expanded rail service could provide another transportation option for people traveling between the two metropolitan areas while potentially helping reduce some pressure on congested roadways.

However, the project’s substantial construction and operating costs remain important considerations as officials evaluate possible transportation investments.

Another Rail Option Could Cost Significantly Less

The proposed high-speed rail line is not the only passenger rail concept being considered for the Austin-San Antonio corridor.

A separate Texas Department of Transportation study, also conducted by HNTB, examined the possibility of increasing passenger service along existing railroad tracks in the Interstate 35 corridor.

Unlike the proposed high-speed system, this option would use existing rail infrastructure and operate trains at just under 80 miles per hour. The estimated travel time between Austin and San Antonio would be approximately two hours.

Depending on the number of daily trips and the stations included, the estimated capital cost for expanding passenger service ranges from approximately $800 million to $1.89 billion.

That makes the conventional passenger rail proposal considerably less expensive than the $13.5 billion high-speed rail concept, although it would also provide slower service.

Potential Ridership for Expanded Passenger Service

The TxDOT study estimated that expanded passenger rail service could attract between 451 and 2,227 passengers per day between Austin and San Antonio.

The study also examined an eight-trip-per-day scenario beginning in 2045. Under that scenario, annual operating and maintenance costs were estimated at approximately $60 million.

These estimates provide a different perspective on the region’s transportation needs, particularly as officials consider whether faster rail service justifies the significantly higher infrastructure investment.

Freight Rail Capacity Remains a Concern

Using existing railroad tracks for passenger service could also create challenges because the corridors are currently used by freight trains.

Union Pacific, which operates freight trains along the existing tracks, has raised concerns about whether the current infrastructure can adequately support both freight and passenger demand.

The railroad has previously argued that existing freight corridors may not have enough capacity to accommodate both types of service without additional improvements.

This issue could become an important part of future discussions if Texas moves forward with expanded passenger rail between Austin and San Antonio.

What Could Happen Next?

The feasibility studies provide transportation officials with different options for improving connections between the two cities.

A dedicated high-speed rail line could offer significantly faster travel, with a potential journey time of about one hour, but it would require an estimated $13.5 billion investment and substantial elevated infrastructure.

Expanding passenger service along existing tracks could require between $800 million and $1.89 billion in capital investment, but travel times would be longer and freight capacity would need to be addressed.

Further analysis, including funding considerations, ridership projections, infrastructure requirements and coordination with freight rail operators, will likely be important before either approach can move forward.

Conclusion

The proposed Austin-San Antonio high-speed rail project highlights the transportation challenges created by rapid population growth across Central and South Texas. A dedicated 89-mile line could reduce travel time between the cities to approximately one hour, but its estimated $13.5 billion construction cost makes it a major infrastructure investment.

Meanwhile, expanding passenger service on existing rail lines could offer a less expensive alternative, with estimated capital costs starting at $800 million. However, the slower service and potential conflicts with freight operations present their own challenges.

As the Austin-San Antonio region continues to grow, transportation planners will need to weigh cost, travel time, capacity and long-term demand when considering the future of passenger rail in the corridor.

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