I finished several articles in Railway Age and Progressive Railroad magazines about how RR are coping with PTC and attendant problem, which made me wonder, facetiously of course, what if we had to emulate layout PTC. 
Lets see, first off any of those expensive beautifully detailed CPL, PRR position, semaphore etc signals need ripping out 
and replaced with boring Darth Vader hood signals. Then install telephone poles with a miniature antenna or if mountainous terrain, antenna towers. If no wayside signals then install those Darth Vader ones. BTW you need to petition the FCC for radio spectrum allocation for your PTC wayside and locomotive radios, and there is a backlog at the moment.
Now you need to get a computer and software that closely tracks your trains around the layout (Dr Chubb software?). The computer emulates the real RR "back office" that does the heavy lifting of data and operations. Computer assigns moving blocks and checks trains are safe braking distances apart, alerting the DS of problems. Maybe RFID chip on engine and RFID readers spaced every half foot or so along mainlines to give precise locations.
MTH engines with PS3 will have to use DCC and get computer interfaces to keep your trains safely apart. Older MTH and Lionels witth need upgrading with new DCC equipment just like the big boys PTC retrofitting all their road engines. And of course, your chosen DCC needs to be interoperable with any vendors control system.
Oh, and your layout engineers will need to undergo extensive training and certification on who/what/why of PTC before climbing into the cab. And don't forget hiring PTC trained signal and radio personnel. And your layout government now requires up to date asset management as well as precise plans of how you will recover from an "incident" (read accident reporting.)
And all of this has to be done in one week from concept to completion, all out of your pocket with no financial assistance, no deadline extensions given. Failure to comply effectively puts you out of layout running. 
And on and on. No doubt I have left out or glossed over some important parts.
Thanks goodness our layouts are safe from PTC legislation. 
I hope..........
