Most of you know I'm no fan of PTC, given that it cannot save enough lives in 30 years to top one year of grade crossing accidents, and it is not positive, the "P" in PTC. Put simply, "PTC is utterly stupid".
A few years back, a train accelerating out of Niles got a false indication because a maintainer was in the bungalow and didn't follow proper procedure. The train highballed into a siding, barely missing a string of ballast hoppers.
Today, rumor has it that the ITCS installation in MIchigan is down as the locomotive-mounted technology is throwing errors codes or something.
For those that don't find their head spinning, look at it this way: "positive" as a technical term implies [basically, in my laypersons terms] that if anything fails or goes wrong, a high degree of restrictive signal or operation will result to prevent accidents in the absence of continuing PTC information to the engine. Try to find that in either of the above scenarios. It's not bloody positive!
In the first case, we just forgot. The whole idea of "positive" train control is that it avoids this kind of human error. In the second case, we just shut 'er down until it gets fixed. Kind of like congress on a recess (the brain trusts that mandated PTC).
Look, my explanations are highly untechnical. I'm just a lawyer, not an engineer. But my ilk - the same people that tried to blame MNCR Valhalla on the third rail and not the lady behind the wheel - will make it really ugly with our eloquent quasi-understanding of PTC when something goes really wrong.
The new Acela: It's not Aveliable.