PTC - delay delay delay - why?

[NW cannonball]

According to this Reuters article

Barely four months before the congressionally mandated deadline, only 11 railroads have told regulators that they expect to begin demonstrating PTC systems in 2015. Others have said PTC demonstrations could start as late as 2020.

The FRA did not say specifically which railroads can meet the December deadline. But it identified BNSF Railway Co (BRKa.N), Southern California's Metrolink service and Philadelphia's Southeastern Pennsylvania Transportation Authority as the three rail services that have submitted PTC plans. None have been certified

Yes, I know, and most of you all know, that there are problems with the rules, and the details, and ---- blah blah .

But I feel that this totally reasonable, possibly a bit expensive, upgrade -- why is it taking so long?

Almost all road trucking outfits know where their drivers are within a few meters.

As far as I can see (and that's not very far) PTC would save a lot of money for the railroads (like precision dispatching - maybe) and collision avoidance?

Why this long-drawn-out refusal to implement what seems easy-peasy win-win tech?