i can see what you are trying to do in the photo and it nearly works. you have the lead in line with the tram tracks and have isolated a couple by retaining colour. overall though, the image is just too busy - can't be helped in a crowed place though! I think that if you made this portrait rather land landscape, you would have a more simplified image. try cropping it on the right with the bottom right track starting in the bottom right corner.
great imagination!

Thanks for the input, I will try that out!

jKay has some good points. But when I saw the photo without his (hers?) comments I thought: what an useless space down under, why not center it more vertically? When I read jKay's comments I got the idea about the leading tram tracks, but still the large space with 'nothing' is bothering me.
If you want to use the tram tracks as a leading device, I would place the actual subject (the colored couple) on the tracks, or choose another subject if you can't make this pic over, for example the single man on the track with his left hand in his pocket.
But overall, I still like this photo however it isn't perfect imo.

I would crop just above the curve in the left track. That way, the track lead up into the picture much more effectively.
Overall, I very much like this picture.

As a straight b&w this might work fairly well, but would probably still be a little unbalanced. The train tracks are a nice leading element, but the interest is the people. Sadly the people are a bit lost, a bit too far removed.
The selective saturation just serves to make the lack of focus worse. Is it about the tracks, is it about the people??? Selective saturation is usually used to set the focus of interest, but here it just doesn't work.