When I wrote this piece three years ago, I figured PTC equals Prelude To Crewless, judging from the rumors echoing quietly through the industry at the time:
[www.railwayage.com]

Now, those rumors have transformed into outright talking points among railway suppliers, rail execs, and government agencies. Their comments on this topic over the past year would suggest that PTC has now advanced to meaning Prerequisite to Crewless.