I live within sight of the NS mainline through Niota, TN. I have observed NS traffic through this region for 10 year now. Most traffic us unit coal trains with the occasional mixed consist. My young son and I will sit and watch the trains pass whenever we're not otherwise occupied. Recently I noticed a coal drag pass with two pushers in the rear. This was a snowy day and I wrote it off to a precautionary measure due to the weather. However, I have since witnessed the same pushers during fair weather. I know there are occasions when NS needs to simply move motive power, but these are usually lashed in the front consist. Can anyone comment on this change of practice by NS.