[Publius]

The FRED units at the end of a train and the trackside sensors perform much of that function, but only to relay the condition of the train to the conductor and the dispatcher. Positive Train Control is the real answer to these kinds of operator errors.

[LouieFisk]

I see what you mean. Though there you would still have the possibility of “error by computer”.

http://gpsworld.com/no-positive-train-control-on-train-that-derailed-over-i-5

“PTC makes it possible to monitor the location of the train and the speed at which it travels, by using GPS and sensors placed both in the trains and along the tracks.

A computer system centralises the data and prevents any excess speed, any red light or collision with another convoy by acting on the locomotive instead of the driver, to curb if it goes too fast, or stop it completely if an obstacle has been detected on the tracks for example.”

[Myrddin]

PTC coupled with ECP brakes. ECP can reduce stopping distances by 70%. A PTC trigger would be an ideal add. My FRA project in 2008 included auto-couplers from Sharma & Associates that make up the coupler, air and ECP power with no human intervention. I had added capability to create an "auto consist" that identified the order and orientation of all the cars and displayed on The WiTronix display. That all died a sudden death when Obama took office in January 2009.