Rush earlier was saying it had to do with a GPS frequency allocation. That, of course, makes no sense, since the GPS frequency allocation is a long settled matter and, in any case, not specific to trains.
It turns out to be a typical question of government bureaucratic turf having nothing to do with spectrum. The only reason the FCC is involved is because it does have to do with antennas, and antennas have to do with radio, and radio is communication. Hence, the FCC gets to sign off.
The FCC is too busy supervising the internet to get itself out of the way of positive train control. From the LA Times:
To make PTC work, freight railroads will use advanced signaling systems that require the installation of about 22,000 antennas, which requires Federal Communications Commission approval. However, the FCC recently directed the railroads to suspend antenna installations while it develops a procedure for addressing possible historic preservation and environmental review issues.Until the FCC develops a workable procedure, installation of the PTC antennas is at a standstill.
Since when did the FCC become responsible for historic preservation and the environment? What ever would we do if there were no FCC? What if we could make them sign off, period, as opposed to signing off on stuff far from their bailiwick?
https://www.fcc.gov/document/220-mhz-spectrum-swap-approved-facilitate-positive-train-control