Although it’s a clickbait staple, i.e. “THE TERRIFYING JAPANESE BRIDGE YOU DON’T WANT TO CROSS!” - the Eshima Ohashi Bridge in Japan is not quite as terrifying as it looks. Most of the “terrifying” pictures of the bridge are taken from a distance using telephoto lenses that, due to perspective compression, tend to eggagerate its height and slope. The bridge's actual grades are 6.1% on one side and 5.1% on the other - you'll encounter steeper grades on mountain highways.
That being said, you're never going to get me to ride a bicycle up and down the damn thing, especially since there is not a protected bike lane on the bridge and so heavy trucks pass within a few feet of you.