i don't paint yards, just photograph, but even that's dangerous if you are into that. Don't ever underestimate the yard. Freights can go in either direction, so even if you don't see the locomotive the end car can still move. Don't trust the rail-signs either. I used to think that if the lights were red the train couldn't go in that direction..got a nice surprise when the freight moved that way anyway. Like everyone has said, dont cross under trains, thats just plain dumb. Some of the best writers in the world who knew "everthing" about yards have been killed. Never let your guard down...i walk like that cat on Charlie Brown Christmas with my head back and forth at all times. Plus don't get caught up in the action and not be aware of your surroundings, a lot of times I see graff and go straight for it not noticing all the bums around...not a good idea. Always remember that trains can come at any time...you may know the schedule like the back of your hand, but trains are late and early sometimes and freights are unpredictable.