Derail is the only map in MW2 where the routes are mostly unpredictable. Most would predict the buildings, but those are noob traps.
derail was so perfect for stealth sniping. M21 silenced if you went prone in the trees worked so well with the ghillie suits. I almost never went inside the buildings. I stuck to the sides of the map honestly IMO MW2 had some of the greatest maps ever I liked the larger maps