I have been messing with my NVidia control panel to get better fps in TSW and here are settings that have worked for me.
Rig First, and it is a high end rig.
Processor Intel(R) Core(TM) i7-5930K CPU @ 4.2GHz
Video Card NVIDIA GeForce GTX 980 Ti 6GB
RAM 32 GB
Samsung SSD
Krait X99 Sys Board
Operating System Microsoft Windows 10 (build 14393), 64-bit
Resolution 2650x1140
I have in game settings all at their maximum with the exception of 'Screen Percentage' which is at 100%
Windows Mode-Fullscreen is also set
I have VSync off as I have a GSync monitor
I can get 35fps out on the line (Powering America Pt2) in the rain and fog and anything from 30 to 50 in the yard on the 'Clear Cut' scenario in Cumberland Terminal.
Using the NVidia Control panel I set TSW Program Settings as follows.
This is an in game Cab shot in the yard showing fps