EC wrote above:
[[ They've had 7 bloody years!!! What sort of extension they looking for, another century? ]]
EC, you may have expertise in the military or perhaps in intellegence, but you have absolutely NO idea about railroad technology, particularly how that technology could be made to work in America.
Back about seven years ago, when Congress first passed the ridiculous "postive train control" law, they attached "a time frame" to the law knowing as much as YOU know about what it would take to design and implement it upon thousands and thousands of miles of un-equipped railroads. (ALL railroads in America are "un-equipped" with PTC, other than 156 miles I mention below).
It's far easier to order on paper that such systems be installed, than it is to make them theoretically workable, and then get them up-and-running out on the line.
Many railroads already have some levels of train control installed (that provides some protection, but not what the Congress demands). Only Amtrak has a true "positive train control" system (between New Haven CT and Boston MA). But Amtrak's system is designed for passenger trains, and as installed would wreak havoc with the huge freight trains that currently run on most American rail territory.
I'd reckon that even if the railroads stepped up their efforts and expenditures, it will probably be 10-20 years before they can get all the track mileage affected by the law fully functional.
Fearless prediction:
Congress will have to amend the law and extend the implementation date.
If they don't, we'll see the trains simply stop running, if to keep them running means that the railroads will be deemed "in violation" of the law.
