"Thank you for your thoughts on this matter, I didn't read them. Here is a boilerplate statement espousing all the great things about this bill that you specifically criticized in your message to me. Please don't reach out again."
If a local government can’t get a hundred yards of sidewalk paved when one of the leaders is pushing for it, how long would it take the federal government to build high speed rail?
Honolulu started planning theirs in the 1960's, finally got funding in 2005, started construction in 2011 (planned to finish in 2020), went over budget, changed plans to shorted the route, and finally opened the first stations a couple months ago. Their current estimate is that it wont be done until 2031. So to answer your question, it can take at least 26 years once you get funding.
https://www.hawaiibusiness.com/hart-history-hawaii-rail-project-when-finished-budget/