We've stayed there a few times. Trains didn't bother us, but of course, my "other" hobby is model railroading and just sitting and watching trains pass. So any train noise was actually quite appealing for me.
Here's some photos of from the fairgrounds. We've been there for a few events and when we were there, we were parked closer to the building near the event. They have hook-ups all over the place, and usually they assign you to a spot, depending on what you are there for. If you are there for an event, they will park you near the event, along the roads between the buildings. If you are there just passing through on your own, you'll probably end up in the actual campground.
Or, you may end up parked along the race track too. Anywhere is possible:
Event camping: (This was a few years ago with our previous camper). One water spigot was shared between 10 different campers. Everyone kept adding on another Y adaptor and everyone had water and sewer. It was a strangely wonderful experience:
Here's another camping area, near the "infield" (race track). Actually, this array of campers was VERY impressive!
On another visit, we were not there for an "event" and we were put in the main campground area. On the other side of that tree line are the railroad tracks. The below photos are suppose to be a panorama type of photo array. That 5er is not mine:
Like I said, the rail road tracks are on the other side of those trees.
This our our camp site. If you look in the background, you can see some of the white buildings, where they park the campers for events:
Here was our spot, facing the other direction. See the tree line? That's the railroad tracks: