The interesting question in my mind is not what the FRA regulates, but what they do not. For many years they apparently simply choose to limit their involvement with the C&TS to locomotives, until something got their attention and in 2000 they suddenly and aggressively exerted jurisdiction over track. They always had the right to do this because of the both the interstate nature of the railroad and the public crossings, but for some reason did not do so until 2000. What else is out there that the FRA could be regulating, but so far has chosen not to. The public crossing issue covers a lot of folks. It is probably some combination of visibility, percieved (political) risk, and resources. But over time most operations should be prepared to deal with the FRA. Which is not all bad. Just sometimes burdensome both in terms of bureaucracy and the potential for differing opinions.
JBWX