I can tell you though, the best two parks IMO to get roller coasters running in the same place is 1)Cedar Point on the MF midway you can get even 3 maybe more coasters in the picture with some good patience. It's very easy to get two over there. 2) Geagua Lake, with Dominator and Thunderhawk so close, those two are almost always running at the same time making it very easy to get many shots of them together, in quite a few pictures of taken, it look like they are dueling or racing due to their first drops and when Thunderhawk does some flips by Dominator's hill. Also at GL it's easy to get Head Spin and Steel Venom in the same shot though it might take 3 or 4 loadings.
*** Edited 7/27/2004 2:25:17 PM UTC by RollerCoasterGod***
Heh. I never even noticed the second train in that photo. I was disappointed in a lot of those pics from BeastBuzz - I acidentally bumped my camera into auto ISO mode and with the light quickly going away, many of them got blurred trains like that.
Fine if it's done right and it's the effect you're after, but horrible looking in shots like that one. :(
As far as finding LNM with trains in both loops, not sure how much it happens by chance, but it'd be an easy one to composite.
For what it's worth, I have a pic of LNM with trains in both loops, taken from the bridge over the lake with a disposable camera. It was an awfully long distance shot to take with that little camera, but you can see trains in both loops. I don't have it in a digital format right now, but I can change that.
When LNM runs three trains, they meet in the loops frequently, but not all the time. If you are in the park and they are running three trains on the coaster, you may have to wait a little to get trains in both loops. When I got my pic, I could see that the timing was getting closer and stayed on the bridge until I got the pic I was waiting for.