Un-signaled Crossings

Watching some videos this morning of CSX trains operating over former Pan Am trackage in Maine, I was wondering what if any rules apply to un-signaled crossings? On several videos you can see trains crossing at decent speeds (25 maybe?) blowing their horns and crossing roads with only crossbucks and yield signs. Down here in Florida, where I am now, you can pace CSX at 60 mph crossing some roads and private crossings with only a yield sign or occasionally a stop sign. Anyone know what regulations are in effect? Something to do with road traffic volume maybe? Is it a State issue or a railroad issue? Who makes the decision on what protection is necessary?

Federal regulations defer to states to determine what protections are needed at specific crossings, but do have requirements for crossings on railroads operating over 110 MPH. US DOT maintains a Compilation of State Laws and Regulations Affecting Highway-Rail Grade Crossings. It's likely that since the compilation covers laws, that individual state DOTs maintain separate regulations. DOT also has a handbook, but that's not standards, it's just advice.

The other option is track speeds are slower in Maine than Florida.

In my past time on Southern's MofW, besides signaled Bell/Gate xings, we had simple Crossbucks, and some non-marked farm-crossings. Private xings were covered under Agreement, at the user's liability, and several went just to the owner's house. But this was in the 60's - 80's.