Time for a Sonic Adventure fun fact. Some here may know that the first "leaked" shot of Sonic Adventure was from E3 1998. SA1 wasn't revealed at E3, but the May 21st, 1998 New Challenge Conference in Japan, where the SEGA Dreamcast was unveiled, cycled through various publications. Some noticed a shot that vaguely resembled an untitled motorcycle game, and others correctly guessed that it was the new Sonic game.

As it turns out, someone uploaded the full conference on YouTube. There was another one, but it didn't have the montage.
https://files.catbox.moe/m19yxp.mp4
There's a small montage showing various upcoming games and tech demos (one of the DC tech demos features NiGHTS). This is where the "leaked" shot of Sonic Adventure is from, and for the first time, we get to see it in motion.
See here:
https://files.catbox.moe/i48hld.gif
https://files.catbox.moe/rqu6km.mp4
Also, it's an early version of Speed Highway Act 1 before they added two textures to the road's walls.