The picture that you took, with the camera sitting on top of the rail, is the running rail. The inner rails are the guardrails, they shouldn't be too shiny... may be a little, because they're used rail, but your photo was taken directly above the running rail. Hope that makes sense.
Does, I actually setup my Camera sitting ON the rail, and snapped, with this SONY Alpha nex 5, its a real small form factor DSLR so the lens is almost on the rail.
I took the fire shots at real low iso, I cant remember I can go look at the exif info.. I bascially setup my Tripod REALLLY low, and pointed at the fire with the city in the background, Fire is relatively easy to pick up, then I set the delay on the timed exposure to get the contrast rising off the fire, it was on top of Farmington Canyon.. cant wait to get back up there