These are some of the spans from my old singleplayer world (now a server that my friends and I play on). I built mostly in a large-biomes extreme hills area, so most of the bridges are between mountain peaks. I'll list them in the order of their construction:
1. Blackstone Bridge
Stone arch bridge spanning a valley between two mountains. There is a 3-block wide roadway across the top, and a rail line running through the trusswork.
View from the road on the valley floor.
2. Kaizo Canyon Bridge
This suspension bridge carries my world's main east-west highway out of the east gate of my central mountaintop base.
3. Fuzan Viaduct
This is a cable-stayed bridge just to the northeast of the previous bridge, spanning the next valley. The central tower is all pillar quartz blocks with a ladder inside, and the valley is home to a sort of enderpearl mini-golf course.
The right deck carries the highway, while the left deck carries the main eastern spur of my railway network.
4. Verdant Gorge Overpass
Two-span stone arch bridge that carries the main north-south road out of the south gate of my central base. The spawning floors of my original hostile mob farm actually lie just below the central pillar inside the mountain.
A different angle...
5. Bowstring Viaduct
A wooden arch bridge across a lake and part of a plain, located on a remote stretch of highway near two plains NPC villages. This design was inspired by youtuber BDoubleO100's bridge connecting his modern house to the spawn town on the Mindcrack server (season 4).
The second and third arches crossing a section of plains and a small pond. All of these bridges were constructed in vanilla survival, and designed with the default texture pack in mind.