California High-Speed Rail Construction Package 1: A Probabilistic Chain Analysis Autopsy

California High-Speed Rail has experienced a sustained cost escalation from the original 2008 baseline to the current programme estimate. This paper applies Probabilistic Chain Analysis to the Authority’s published business plans and risk narratives, showing that the programme’s cost growth was driven by correlated dependency chains that were not quantified in the published risk framework. Using public documents only, the paper reconstructs the main cascades linking right-of-way acquisition, utility relocation, design rework, procurement timing, funding gaps, and inflation. The result is an auditable open research record intended for reuse, verification, and further analysis of infrastructure risk modelling.