Extremely minor nit, but it should be point out that Japan is cost efficient because they've mostly built out their "easy" terrain, especially for Tokaido line

Extremely minor nit, but it should be point out that Japan is cost efficient because they've mostly built out their "easy" terrain, especially for Tokaido line (the current Tokyo-Osaka line). The Shin-Hakodate to Sapporo extension will cost them 1.24T yen for 131 km of many tunnels and bridges [0], or US $83M/mi. This cost is why it's taken Japan so long to build a complete Tokyo-Sapporo HSR line, even though the Tokyo-Sapporo air route has been one of the most popular air routes for a long time [1]. They're also working on the Chuo Line which is a new Tokyo-Nagoya-Osaka line going through mountainous terrain that will facilitate 67-minute travel between Tokyo and Osaka. This line will cost 9T yen for 438km [2], which will be a whopping US $187M/mi. Funnily enough, speaking of the Tokaido line, the president of Japanese National Railway and the chief engineer resigned before its completion due to cost overruns [3]. Japan makes it look easy, but the Shinkansen had a troubled start. In comparison, for the CA HSR [4], the fairly flat Central California portion is costing $19.5B / 199 mi ($98M/mi) while the more challenging Palmdale-Burbank section is costing $16.8B / 41 mi ($382M/mi). I know you use it as a figure of speech, but all of this means that a US intercontinental line going through the Rockies would be difficult. Still, I would love to see an intra-Texas, Midwest, or East Coast HSR in my lifetime. [0] https://www.town.kutchan.hokkaido.jp/town_administration/shinkansen/ninnka/ https://www.town.kutchan.hokkaido.jp/town_administration/shi... [1] https://en.wikipedia.org/wiki/List_of_busiest_passenger_air_routes#World https://en.wikipedia.org/wiki/List_of_busiest_passenger_air_... [2] https://en.wikipedia.org/wiki/Chūō_Shinkansen https://en.wikipedia.org/wiki/Chūō_Shinkansen [3] https://www.bbc.com/culture/article/20140714-built-for-speed-the-bullet-train https://www.bbc.com/culture/article/20140714-built-for-speed... [4] https://hsr.ca.gov/about/high-speed-rail-business-plans/2020-business-plan/ https://hsr.ca.gov/about/high-speed-rail-business-plans/2020...