Having worked with several of these firms doing location and coding of things like freeway traffic sensors, I can only say, I wish that these firms had been tasked with developing PTC. It would be done by now, for less, and likely have more reliably.

Don't get me wrong, even this costly PTC system will be an improvement over today's systems. But the excessive costs and complications have come largely from FRA taking input from existing vendors, and trying to keep all of the current vendors of signal systems "in the game", leading to a much more difficult integration, of often obsolete signal and detection systems.

Sometimes one should actually throw out the old and replace it. Kind of like what's been learned from the Air Traffic Control "upgrade" fiascos of the last twenty-five years......

This RR crossing location data integration will be a necessary integration to complete the data sets for full automation of the Google car.... when we finally take the "chimp" out of the driving loop completely........look ma, no hands!