Remember we're not talking about starting from scratch here. An extensive track network already existed in China before they started electrifying and upgrading tracks for fast trains. As it does across North America;
US;
https://stb.maps.arcgis.com/home/webmap/viewer.html?webmap=96ec03e4fc8546bd8a864e39a2c3fc41#!
Canada;
https://rac.jmaponline.net/canadianrailatlas/
https://ontheworldmap.com/mexico/mexico-railway-map.html
Every piece of track electrified or upgraded adds value to the network as a whole.
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