I can tell what this a bug but it's really a bit uncomfortable: The brightness in tunnels isn't detailed cause when you enter tunnel the train is still bright of weather and in the cabin too: you can see this brightness because of sun shining through the tunnel. Can you fix this or it's a problem because of video card Nvidia GeForce 960 2gb VRAM?
I doubt it, there where no fixes in the last patches for the sand patch route and i guess there wont be one in the future.
Anthony Pecoraro: Tunnel darkness was introduced with rapid transit, but never was fixed in the sand patch route. Still bright trains in the dark tunnel.