Indeed two tracks w/trains easily out do 8 lanes of SOVs as CTA stated half a century ago in the direct comparison of the Congress (now Eisenhower) Expressway to the tracks in the median. So, the cost of construction of ANYTHING in the US is astronomical, the real issue is what is worth those expenditures. As this is not a muscle car afficionado site, one would think the default answer is rail. It is of course, not that simple; social policy is not logic driven but rather a "sausage" produced by advocates,lobbyists, idealists, bribers, patronage distributors, and all of the others with agendas both noble and evil. Some of us actually remember when you only needed a car to access national parks and other rural areas.