Promised to voters more than 15 years ago, the California High-Speed Rail project is over budget, behind schedule, and now, by law, must finally explain exactly how it plans to finish the job and pay for it.

Gavin Newsom has signed a bill requiring the rail authority to elaborate a funding path for the Merced to Bakersfield segment in its business plan.

Now, there's a push to start construction in Gilroy, connecting to the Caltrain station there. However, development all hinges on state lawmakers approving billions of dollars in funding. Another blow for the project came earlier this month when President Trump said he's pulling $4 billion in federal funding.

California's High-Speed Rail project is facing challenges, with costs currently $100 billion over budget. This video examines the reasons behind these difficulties as the initiative aims to connect San Francisco and Los Angeles with the first full-scale high-speed rail line in the United States.

U.S. President Donald Trump said on Wednesday the Transportation Department is rescinding $4 billion in U.S. government funding for California's High-Speed Rail project.