The California bullet train is facing at least another billion dollars of proposed cost increases from its contractors, following a history of sharp cost growth on construction work over the last eight years, The Times has learned.

The state’s High-Speed Rail Authority has mostly approved such increases in the past, and if it does so again, contractors could proceed with one of the biggest price escalations since bullet train construction began in the San Joaquin Valley.

The continued cost increases — and the likelihood of similar problems surfacing over the next few years — are deepening the already difficult financial condition of the $100-billion project.

The state has budgeted $22.8 billion to build a partial segment from Bakersfield to Merced. Originally, construction of the Los Angeles to San Francisco system was pegged at $33 billion. But the surging costs will probably force the state to dig deeper into its future funding just to complete that 171-mile leg in the valley.

Read the full story on LATimes.com.