To support ARCHES and California’s commitment to hydrogen, the UC Davis Hydrogen Program2 evaluated the requirements and costs of building a network of hydrogen stations (including delivering hydrogen to those stations), and the costs of purchasing these vehicles, including light-, medium-, and heavy-duty vehicles. This work builds upon our prior studies3 that developed two FCEV adoption scenarios through 2045: i) an ambitious but incremental Base Case scenario closely aligned with FCEV sales targets adopted by ARCHES, and ii) an even more ambitious High Case scenario that assumes robust light- duty and medium/heavy-duty vehicle markets by 2030, along with more rapid growth in refueling and hydrogen production capacities throughout the state. We used the two scenarios to estimate the level of investment and other costs for building out a hydrogen system to support road transportation (i.e., trucks, cars, buses), and examine how these investments and per-unit hydrogen costs play out over time (with 2030 and 2045 being key years) and across different types of hydrogen system components (e.g., hydrogen delivery systems and stations). We also looked at workforce and jobs impacts from the transition to hydrogen and FCEVs within the state.