Bridge design

[Fernando Esteves]

Hello people!
Happy New Year, everyone!!!

I'm thinking in design a bridge that goes on the this way (would have some thin details, but structurally would be this)
But I heard that there are some requirements, like the outer parts need to be over the X bracings, things like this.

What do I need to observe to make it structurally functional, with the ballpark look of this?

Thanks a lot!