Couldn't find a general PTC thread to post this question on so picked this one. To those more in the know did I read correctly somewhere that MARC is using Amtrak's I-ETMS overlay for some diesel equipment that operates on a portion of the NEC? (while their electric locomotives are using ACSES II) I had heard about the overlay for Norfolk Southern tenant freights but never heard about a passenger tenant using it. Where is MARC running diesel locomotives on the NEC - are these for trains that extend to station stops outside of electrification? Not all that familiar with MARC as its not my backyard.