The double track crossing (both railroads are double track at this location) is known as IRIS on both railroads. It is an automatic interlocking with all signals normally displaying "STOP". Whether it is an FEC freight train or a Tri-Rail commuter train, the first one to hit the approach circuit will automatically get a signal to cross the diamond. If for amy reason the signals are not properly working there are rules in both timetables and rulebooks that apply and will be followed in order for the train to continue. Incidentally, there is no actual track connection with the two railroads at this location, in order to accomplish that, a train has to use the FEC/CSX connection at Oleander which is near the southside of the Miami Airport. When I rode the Amtrak Inspection Train last year it took us just over an hour to go from the CSX/Tri-Rail to the FEC at this location with a brief stop at the FEC Yard enroute.
Noel Weaver
Noel Weaver