Now I Understand About The Aws Learning Curve Lol!

A double yellow isn't that bad. You know you have another signal before you have to stop.
I'm pretty sure that in the video one of the scenarios is wrong, where the dispatcher dispached the train on a red signal. I believe the correct procedure for a platform dispatcher is to wait for the signal is clear before dispatching the train.

 

That's what the DRA is for. Any time you stop facing a red (or buffers) you set the DRA: this disables the throttle for the very reason you cite.

 

"...doesn't govern anything other than the driver being awake enough to shut off the horn. "

 

I don't know about US rules but assume they don't have TPWS so this doesn't apply. Certainly you don't SPAD by going through a yellow (caution) because SPAD in the UK refers specifically to red (Danger) signals

 

I thought it should be used at any caution or danger signal... Live and learn

 

The alarm is quite loud. Loud enough to grab the drivers concentration. A lot of drivers will already have their hand positioned to press it when approaching signals. I aids in keeping the driver alert.

 

How to react to a double yellow is very situational, and requires some analytical thought. If you can deduce that you are following another train, then you can "surf the yellows" without slowing down much if at all. OTOH, if one pops up out of nowhere then there is probably a good reason to start braking, whether approach control or an upcoming hard red.

Generally I only start getting concerned if I see a single yellow.

 

Given that it cuts out the throttle, it isn't something you want to activate while in motion.

 

I should explain. I thought the DRS should be set when in platform (ie stopped) and any caution signal was showing