What do these signs mean...?

Question

I live near train tracks. and I saw the Union pacific truck out there today, these guys put up these signs, on the side of the tracks. Not near any roads. They are about 4 feet high. There's 2 ones yellow with a big red X in it, and the other is all yellow.
They dont say anytihng. But they pull right out of the ground, so they can be switched. What are they for?

Answer 1

These signs indicate that there is a temporary speed restriction two miles ahead. Usually a speed restriction is put in to effect when track work is being done, or is scheduled to be done and in the meantime a slower speed is required over a portion of the track that isn't safe for the regular speed. The signs can remain in place for a day, or up to a few months. The engineer and conductor also receive a written copy of all restrictions they will encounter prior to each trip. Each railroad is somewhat different and I'm not sure about the red X. On the line I work for, a yellow sign is simply a slower speed ahead. And a yellow sign with a red border indicates a stop 2 miles ahead and you must contact (by radio) the Foreman incharge to receive verbal instructions. The Foreman may give permission to pass the restriction (or Form B on some RRs) at a certain MPH, or he may have you stop if he has men and equipment working on the track.

Answer 2

Derail is right.

A yellow "flag," (flags can be of any material, not just cloth, as the common flag is concerned) indicates a temporary speed restriction lies ahead.

The "Red/Yellow" flag indicates the the track ahead is either occupied by maintenance of way or out of service. Here, permission must be received from the foreman in charge of work before passing the next flag, which will be "Red."

When a yellow flag is displayed, the train can proceed at the indicated speed, and that speed may not be increased until passing a "green" flag. Where temporary speed restrictions overlap, only one green flag is to be displayed at the end of the last restriction.

But, speed and other restrictions, including maintenance of way, are delivered in writing in the form of Track Bulletins for crews going on duty, within defined limits expressed in miles, and restrictions must be complied with, even in the absence of any flag.

So, even if changed around by vandals or other ne'er-do-wells, it will make no difference. The flags are merely reminders for restrictions you have already been issued in writing.

Good question.. Thanks for asking.

Answer 3

I'm no expert but it might have something to do with the way the tracks are, so that train drivers know which way they are going to head. Like the X would mean that the train will turn, and otherwise the tracks go straight.