"How is this possible if the final elevated guideway segment with stations is expected to cost approximately $1 billion?"  Me thinks Mr. Wilson has factored in the guaranteed CHANGE ORDERS that will occur based on the prior segments?  Also, he's probably factoring in the downtown obstacles ahead (why did KIEWIT bail?).

And lastly, why did Captain Kirk say he needs 10 or 20 years more of the tax to have enough for construction?  Doing the math that's another $3-$6 billion based on current annual "rail revenue".