But this
is a broad topic seeing as how Union Pacific is about to be a national operation.
See the Starcom21 database page:
https://www.radioreference.com/db/sid/2324
BNSF - Clearly using SmartConnect based on the listed talkgroups pointing to national use.
CSX - Clearly using SmartConnect based on listed talkgroups, and personally confirmed by myself as used in the Southeast region.
NS - On Starcom21, but not using SmartConnect systemwide. I know this because here in NC they only have VHF.
UP - Apparently using WAVE with the TLK-100's in addition to legacy APX radios.
CPKC - Has talkgroups, unknown on SmartConnect
CN - Has talkgroups, unknown on SmartConnect
So 3 of the 6 (soon to be 5) class 1 railroads covering most of the US confirmed using a form of SmartConnect.