Good doctor,

I agree with OPB, we must have a robust level, at the track circuit, and a broken rail is one good example. The secondary DSRC, would be for confirmation, and redundancy. It could also serve as a two way relay of a greater range of information. And, the needs issues I've seen points toward a system that is layered, and highly integrated with additional enhancement of the existing baseline systems.

I know what your talking about OPB, having been on the "bleeding edge" of some of the early ITS systems application attempts (and watching fortunes spent on ITS fantasies-like:look ma no hands- "cartrain", or random computer based jitney's--....). I've wasted a bit of FTA Demo money on testing these tracking systems and integrating various other components, on transit, and for arterial streets, but the lessons learned have resulted in some well vetted systems and tested applications.

We learned, often the hard way and usually-no always-the expensive way, as you may have, it's sometimes far more cost effective to do fewer really important functions a lot better, with greater reliability, than to try to throw technology out, and try to solve everything. Good systems live or die on realistic integration needs, that the system can realisticly perform. That is they do something truly needed, better, faster, cheaper..... and, in this case, safer. That is how we got to some good "off the shelf", very robust systems that track, communicate, report, and gives much more control capability to operations, with great accuracy. Those lessons need to be applied to PTC, not relearned.

I agree with the danger of letting the politicians take too much charge of this. It is terrifying. This is because the lobbyists for the competing firms will want to use the regulatory and political process to ensure proprietary technological preferences. And, this type of jockeying has often resulted in delaying competive and effective standards, forcing overly costly standards, even substandard, or damn near useless technology or applications. A lot of that is nothing more than to make sure that these vendors get their monies worth from the campaign contribtutions to the politicians. Not for value added to the consumer. It appears to me that FRA has done a reasonable job, but, at times, had been stymied by this issue?

We will get this thing done, maybe even done right, to improve safety, because we've got a lot of good folks like OPB still on it.