hey that,s nice work brother, really appecative ...hope u r using max scaleline render ...
things u have to look once again ...
first the camera angle, make it a little lower near the groung then your train and the signals will got some size right now it kindda near to a toys mean non approachable and un propsnate ...
about key light must comming from the sun direction..
need a little more work on shadows (contact shadows ..)
put a z depth in the scene
the front right hand side wall texturing is blurring try to fix it ...
i like the mood need some more variations .....
keep comming wating for your next stuff ......
keep rolling.......................