We don't have to "guess"... Studies have been done...
Early Train Operator (ETO, Deutsche Bahn) Side-by-Side Study
The Board requested the ETO to prepare an analysis comparing the impact of the Merced-Bakersfield investment policy recommendation to other comparable early investment options in the San Francisco to Gilroy and the Burbank to Anaheim corridors. This Study evaluated a range of costs and benefits including capital and operating costs, ridership, revenue, GHG reductions and congestion relief. The study was performed in two stages that include a preliminary Qualitative Phase (published October 31, 2019) and a second Quantitative Phase (This report) including the numeric outputs from the different models used.
https://hsr.ca.gov/docs/about/business_plans/2020_Business_Plan_Side_by_Side_Study_Quantitative_Report.pdf
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