Overall, good video. I'm not sure what drone you're flying but you might have tried tracking to fly parallel to the train, camera facing the engine. If you're shooting 4K you could even zoom in, in the editing process, for a closer shot (assuming the video is edited as HD, not 4K). For the future, maybe put a GoPro on the ground or on a tripod somewhere (like by the trestle or along a straight piece of track) to have a nice ground level shot to cut in with the train passing. I'm impressed you obviously drove out to the middle-of-nowhere to get the shots!