By David Shepardson

WASHINGTON (Reuters) -Two senior congressional Republicans asked the U.S. Department of Transportation on Wednesday to disclose documents detailing a decision by President Joe Biden’s administration to award billions of dollars to a California high-speed rail project that they doubted would ever be completed.

Sam Graves, who chairs the House of Representatives Transportation and Infrastructure Committee, and Ted Cruz, the Senate Commerce Committee’s top Republican, requested documents by June 12 about the department’s December decision to award the project another $3.07 billion.

California voters approved $10 billion in 2008 for the ambitious project, which aims to move passengers from San Francisco to Los Angeles in under three hours. The lawmakers said the project has experienced numerous delays and rising costs, and that the California High-Speed Rail Authority, the state agency in charge of it, has not identified key funding needed for it.

The full project was initially estimated to cost around $40 billion but has now jumped to $89 billion to $128 billion.

A spokesperson for the state agency said it takes the issues raised by the two lawmakers seriously and is ready to respond to the Department of Transportation and the Federal Railroad Administration, which is part of the department.

Graves and Cruz cited a 2023 review by an independent body that concluded that the project faced an “unfunded gap of $92.6 billion to $103.1 billion between estimated costs and known state and federal funding” for completion of the full system.

“Despite evidence that continues to show that the California High-Speed Rail project has critical issues indicating there is no reasonable path forward for successful completion of the project … the Biden administration continues to allocate substantial federal taxpayer dollars on this highly questionable endeavor,” the lawmakers wrote.

The Department of Transportation did not immediately respond to a request for comment.

Transportation Secretary Pete Buttigieg said in December the California project “is facing a lot of the challenges that come with being the very first at anything,” and added that rail project awards face an “extraordinary level of scrutiny.”

The state agency estimated that costs for an initial 171-mile (275-km) segment connecting Merced to Bakersfield have risen from $25.7 billion to $33 billion, and it will be operational by 2033.

It is a major project in California, the Democratic-governed and most populous U.S. state. It eventually is envisioned as connecting Sacramento to San Diego.

The project, which has spent $18 billion since 2006, has received funding from two Democratic presidential administrations amid opposition by Republicans.

President Barack Obama’s administration awarded California $3.5 billion in 2010 and the state has dedicated $4.2 billion to the project. The Biden administration in 2021 restored $929 million for the project after President Donald Trump’s administration pulled funding.

California wants $8 billion in total from the Biden administration for the project and last year won another $202 million in federal funds for grade separation projects. On Tuesday, the state said it was seeking another $450 million in federal funding.