A few minor comments:

> Prior to Dr. Robinson's invention of the closed loop track circuit and the consequent advent of automatic signaling,

Thomas P. Hall started his researches and experiments with electrically operated automatic block signals in 1866, using track instruments for train detection. Track circuit control wasn't widely adopted until after 1873, a result of the PRR deciding to adopt them.

> And yes, where safety and signal systems are concerned; "high speed" means any speed that does not permit a complete stop at a safe braking rate, within one half sight distance; to any obstruction, broken rail, kink,

Since when do signal systems check for kinks in the track?

> This inadequacy requires the replacement of every track circuit in America where PTS is to be installed;

Last I heard, the FRA won't permit the abolition of track circuits (in favor of GPS) because they are the only way to detect broken rails.

> As it is, Amtrak's version (North East Corridor) which predates the PTS mandate, is far superior to that foisted upon the railroads, does not rely on the foibles of GPS and uses cab signalling technology to its max; and it does work.

Amtrak's coded track and cab signal system was first installed in the mid-1920s - - - following a 1922 ICC order for installing ATS/cab signals on certain railroads. For PTC, Amtrak uses the ACSES II system, which was developed jointly with Siemens and is based on the European ERTMS system. It's an add-on to the cab signals.