Railroad police are spread pretty thin.
In most of the ex-Conrail territory that Norfolk Southern got in the split up of Conrail (between NS and CSX), the old Conrail police channels are still used...albeit very infrequently. Conrail still exists as a jointly owned entity (NS and CSX control) in three markets - North Jersey, Philly/South Jersey, and Detroit. This was done because there was no way to break up the assets in those areas to make all the parties involved happy. I do not believe that the remaining Conrail has any police...they were all transfered to either CSX or NS.
In the Philly area, I will sometimes hear an NS Police officer calling in to their central police dispatch (based in Roanoke, VA) on 160.560. NS-1000 is the callsign for the central dispatch.
CSX Police in Philly always used to communicate with train crews on the 160.230 road channel for the CSX Philly Sub. Car-car chit chat was on 160.875. As far as I know, CSX does not have a centralized dispatch center for their police...info is pretty hard to come by for CSX. I'm not near enough to any CSX ops to routinely monitor for infrequent police traffic. When I lived along the Philly Sub, I used to hear the PD talking to trains stopped in Darby and SW Philly and also working in the Eastside Yard and old Snyder Ave Intermodal Yard in Philly.
Norfolk Southern Police have their own website:
http://nspolice.com/
Cell phones and/or Nextel are used heavily. Some RR police may have access to local police channels or radio systems depending on the working relationship they have with local jurisdictions.
The most likely place to encounter a RR cop on the freight systems is in terminal areas (especially intermodal yards where theft is high) and in high crime neighborhoods where trains may have to stop for long enough periods of time that they could be burglarized.
