Scote: Thanks. There will be 2 boys and woman in the foreground and a few other characters in the background. I am not sure exactly how many I will make. 
Gadzooks, Thanks 
Leigh: Thanks I really appreciate your feedback.
Good point on the composition. I have tried adjusting it a bit, by turning the camera a bit to the right, making the picture format a bit wider and by moving a few of the objects. The tracks still exit in the right side of the picture :shrug: But at least it is closer to the corner. I suppose I could move the newsstand and the camera to the right aswell. That might do the trick.
The central characters will be 2 boys and a woman. I want the woman to be the main focus of the picture so I want to use the rule of thirds and place her near one of the intersecting lines.
The newsstand plays an important role as I am planning on placing the 2 boys near the gum dispenser.
I really like your idea with snow on the trains and water on the platforms. I have already modelled a few characters without winther clothing, so I might make it rainy instead of snow…or change the clothing of my characters. I will have to do a few tests. 
I haven’t made the final lighting yet. I want a more dramatic light in the scene than what I have here. I was thinking a bit like that famous black and white photo from Grand Central Station. I can’t quite get the look that I want straight from the render, so I think I will have to render a few passes just for some of the lightsources and fix it in Photoshop.
Here is a new test render:

Edit:
Here is another test where I’ve moved the newsstand and camera a bit to the right
