I didn't worry about polygon count because I wanted to create some static image not an animation. The model of the train isn't the cleanest model and polygon count for it is quiet large. I tried to achieve the shape that I need.
Lighting in this scene is very simple, it consists only one direct light. Here is picture with different views of the scene with light source in it:
As you can see from the image above, direct light have quiet simple settings. The most important is that multiplier was set to 1,5 to create light like in summer shiny day. Color for this light was turned to the pale yellow to simulate the sun.But before this solution I have spent a lot of time, testing, trying and changing different types of lighting, here some of this light tests:1 direct light + photons = "midday"