Gents,
yeah those tracks are used, both by CSX and by the Gettysburg Railroad Sightseeing Company (located on Washington St, right by the college (I used to live across the parking lot from it).
the cut where Blake took those shots is the more imposing section of the line, further west, where I think the original picture posted, the cut is shallower and more overgrown with vegetation (as you can see in the photo), but right where the Wadsworth Ave bridge crosses the cut, it is deep and has very steep and tricky to climb sides (I did it when I was out there at school a number of times, but I can't imagine doing it under fire (in fact, those Rebs from Davis' Bde who surrendered were the smartest). Blake, just opposite the bridge (in your photo looking NW) and up atop the cut, is the 14th NYSM statue (one of 3 they have on the field; more than any other unit at Gettysburg) and according to the flank markers near the bridge, it is actually the exact location of the charge conducted by the 2nd Wisconsin, 14th Brooklyn and 95th New York that rounded up a good portion of Davis' Bde.
Ok, to get back on topic, only in some area's should the cut be impassable as a hex-side...like by MacPherson's Ridge...further west...not so much..maybe have a stone-wall to visually represent the cut, but that way it doesn't impede movement AS MUCH.
I've walked those tracks a good many times Blake, seeing those pictures you took was like having flashbacks!

<salute>