A passenger locomotive is due to appear in Grand Theft Auto VI, shown pulling three Viewliner-style coaches through Port Gellhorn in a postcard on the promotional website. The silver, blue-striped engine appears to be based on the GE Genesis line of passenger locomotives, judging by its body shape, roof exhaust vents and small side windows.
Vehicle data via GTA Wiki (Fandom), CC BY-SA 3.0.