I designed this railway bridge for my city in stud.io. The eagle-eyed/well-travelled viewer may recognise it as being based on
Laytown Viaduct. I went to the beach there last summer and crossed the footbridge alongside it and knew it was a design I'd want to recreate in Lego some day.
The XXXX pattern of trusses isn't actually connected to anything, it's just held in place by other parts around it, which I'm pretty confident should work out ok when I eventually build it for real.
I considered different colours, worried that teal (or dark turquoise as we're apparently supposed to call it now) parts would be too rare. But in the end after considerable research into the availability of teal parts I decided to stick with it, for as much variety as possible in the city, and because there will definitely never be a teal train running across it.