I wonder if it's like the double-decker passenger cars used for Metra in Chicago. These trains never change direction (like Amtrak) but just run forward (IIRC) into the city and reverse back out to the suburbs. The car on the end has a small cab where the engineer sits and controls the train when it is running reversed. From the outside the difference between that and a passenger car is pretty subtle.
Ha! I’ve always thought that all the Metra cars were identical and each one had a cab for when the train is heading into the city (Metra always configures trains so they “back into” the Chicago terminal (Union Station/Ogilvie/LaSalle).
Like the CTA (and the South Shore) trains - every single pair could be be the lead. They all have a spot for a driver (engineer?)
