Hey Jana,
this is going really well! Love your sense of design and composition.
One thing I would adjust is the trolley image. It is starting to have what I call "perspective creep". Perspective creep is when major elements of an image start to get "pulled" back to the vanishing point (which makes everything too wide). a lot of people do this by accident when designing exterior city scenes. What I recommend is trying to break up the lines leading back to the vanishing point by intersecting them with stronger verticals. Also, your right vanishing point is probably too close and is making the trolley converge a bit too much. If you are standing near a bus or single train car, it doesn't really go back into a vanishing point very much.
So here's a suggested fix. I lessened the convergence of the trolley on the back end. I added wainscoting to the bottom half of the trolly and added small vertical boards there. THen I shrank the size of your boards because they may have been a little on the large size. Lastly, I added a bit more light source to the right side of the trolley so it popped a bit more. These are all just suggestions, feel free to integrate as necessary. : )
I definitely want to see more from this series! You are really on to something here.
-L