Something I have been working on for a few days. Please give me honest critics.

The plain white tones seen throughout the image (especially in the background opening) seems to be detracting from the image a bit (and as a result makes the image look like a generic photo from a flash camera).

I would go with slightly warmer lighting with more natural hues in the far back.

Sorry, nothing to criticise, only praise.
It would take me “a few days” just to make the train.
If I have to nitpick I could say that the graffiti is a bit too light, especially in the wet areas, but that’s it.
Good job

Lattice is too clear, and its need a couple of fog

There isn’t any visible atmosphere and a real focus on the image. Another thing is i am not a fan of the repetitions you got here, maybe do some changes from time to time. Break a wall or something.

Otherwise really nice image!

I also think the modeling and light is very good, the composition is nice as far as I am concerned. Also you must be quite fast if this render took you only a few days.
I agree that the image lacks atmosphere (I mean the feeling of air if that makes sense). You could try adding some dust and a little but of bloom.