Lol. The reason costs are so high is because there is severe political pressure to keep them that way from contractors, unions, etc, and we're rich enough to afford it.

For context, we have 4 million miles of road in the US. So even with $100m/mile, we're talking trillions of dollars before we even get to the actual feasibility of putting rail everywhere.

Rail is great, but there's no world where it does the same thing self-driving vehicles would.

This isn't quite a fair comparison; many of those roads are running through areas with low land values. Comparing ground-level rail through cornfields in Oklahoma is apples and oranges to a busy, high-capacity subway underneath Manhattan.

> Construction cost of subways outside of places like NYC that apparently have no concept of cost control is typically about $100-300 million/mile.

Where within the United States is this true? (note: United States is known for high construction costs)

e: or just downvote me - but I don't know anywhere with a $100 million/mile subway system.