>>2010163>I'm legitimately surprised it wasn't standardized for the completely grade-separated ones.ATC-2 was deployed almost twenty years after ATC-1 so it isn't that surprising they are different, and both systems were updated throughout the years to accomodate the increased in speed before the eventual switch to digital ATC systems.
>Basically JR West and JR Central used the same system because they already had one, whereas JR East and JR Kyushu could go their own way since they were building from scratch?Essentially yes, although IIRC KS-ATC is almost the same as ATC-NS. Also ATC-2 was used in the Nagano portion of the Hokuriku Shinkansen before it switched to DS-ATC in 2013. Below are the years when the switch to digital ATCs were completed.
Tokaido: 2006
Sanyo: 2017
Tohoku: 2007 (DS-ATC was equipped between Morioka to Hachinohe when the extension was completed in 2002)
Joetsu: 2009
Nagano: 2013
