Since Viking isn't going to be doing these collectable location guides anymore, I had a wack at making one of my own for NEC specifically. With a ton of time spent looking around (after which, I can now actually play the route) I got everything collected and a huge guide assembled. The NEC collectables are quite difficult, probably the hardest of any route yet, due to the non-linear nature of the route, as well as a combination of the CSX style with collectables everywhere on the mainline, plus the GWE and RT style of having collectables at the stations. So you can't just hop from station to station and find every single collectable. I do recommend walking around the route yourself and exploring all that's there, but if you really want that achievement, the guide can reveal those hard to find collectables. http://steamcommunity.com/sharedfiles/filedetails/?id=1335251567
So I have all but 2 cone and 1 danger sign great work. I am trying to figure where I missed each of them.
Here is link to the guide this should help you out https://steamcommunity.com/sharedfiles/filedetails/?id=1335251567