Comment by tcbawo

If they build the tunnel at $20k/foot, the cost would roughly be $1.6B. The line will supposedly run every 30 seconds for 20 hours per day. That's 876k trips per year. If they charge $20/ride and it fits 16 people, it will generate $280M/year at 100% utilization, or 17% ROI. Maybe a more realistic number would be 40% utilization, which still gives a respectable 7% ROI.