The issue is not implementing one-man crews. Solo engineers can be found in a variety of operations including helpers, engine-exchange crews, "outside" hostlers, a few RCL jobs and, on some Class II and III railroads, in road service. Many passenger trains are operated with one person in the cab, although that is less of concern to labor as they are almost always accompanied by a trainman back in the coaches. Rather this was an effort to limit or eliminate them. The issue is also being debated elsewhere including pending rules for Conductor Certification and standards for Positive Train Control. In the latter, labor is arguing that display screens are required on what we used to call the fireman's side of the cab to handle mandatory directives. Of course handling a mandatory directive under a PTC system will be somewhat different than taking a track warrant today. Rather than writing critical information down on a prescribed form and reading it back to the dispatcher for confirmation, train movement in PTC will simply appear on the screen and the control system will intervene if the engineer is in danger of exceeding his authority or a speed limit. One might argue that such information could be received by a person at the controls of a moving train (which is not allowed today when copying / repeating a track warrant).