It depends a lot on what the situation is.

What I heard at one training session for firemen was that, if
you have enough people, send someone -- or multiple people --
down the track in each direction, and know how to give a manual
stop signal -- hand or bright object waved side to side below
the waist. At night, use light or flare (fuse). Railroad rules
specify that any object waved violently at trackside should be
considered a stop signal, but I would assume it would be taken
more seriously if it is done correctly and especially if you
have multiple people giving that indication.

In many parts of the country, finding an occupied railroad
office is very unlikely -- even if you knew where the nearest
office would be. Yes, if there's a yard nearby, you could
find someone who would raise the alarm. It probably wouldn't
matter which door you went into.

But, in most cases, I would (1) try to flag down a motorist
who may have a cell phone (assuming there is coverage in the
area), or (2) go to the nearest house or business and either
ask to make an emergency phone call or have them call the
authorities and/or railroad for you. Yes, there are still
public phones, though they are not as common as they used to
be.


In one case many years ago, I saw some broken tie-dwon straps
dragging from a car in a freight train. These straps could
have seriously cut someone at trackside or snagged on a
lineside object, causing a derailment -- or tearing loose
the remainder of the lumber lading. Moments after that
freight had passed, an Amtrak train made a station stop an
unstaffed station. I ran up to the conductor who got on the
radio to report the dragging straps. The dispatcher called
the freight to stop and inspect the train.

-- Ernest