Flagmen

I'm so old that when I hired out the SP still had a few crossings around SF blessed with little shanties sporting the chimney from a coal fired stove. Whenever a train came the real live flagman would put his paper down (or whatever they read before Playboy was available) and went out to flag the crossing.
None of the C&TS's crossings except the one at Antonito are historically authentic, so maybe a shanty and a flagman would do the trick.....no electricity needed.
From a practical standpoint the simple solution is to put a brakeman in a vehicle to drive to each crossing to flag it, and then get on the train at Cumbres. I wonder why that has never been done.