Callsigns and license don't mean much in the railroad radio world. You may hear operations on any of the channelized frequencies.Yep,
and thank you...
When I worked for Union Pacific, I would program a few pairs in there that I kept to myself unless I really needed to speak to my engineer privately. Anyone who wanted to listen in would need to monitor both channels to hear both sides of the conversation. I generally had a code word that I would say that meant to switch to that other pair of frequencies. This was done to prevent prying ears from railroad management.
So, just because there is a license for a certain frequency for that area doesn't actually mean much. Railroads can use any of the railroad band that they want no matter where in the nation they are. Large track gangs come to mind, and the TRT used many all at the same time.