Thanks for your reply.
The sides of the bridge are made from stainless steel. In sketchup I just picked a material without texture en made it slightly grey / blue. Material Finish set to Polished, reflectance set in the middle.
In the railing (I hope it's called like that) there is a LED strip to light up the bicycle path.
The "LED" strip is made just with setting the material finish to glow and lots of invisible lights above the bicycle path to get the nice reflections.
The background is added later after rendering.