Following a similar generation logic as river biomes, but a road with a more consistent width instead. Ideally connecting two to three (or more) villages. Would be a neat place to have smaller structures spawn along it’s length too. It’s utility as a road for travel is clear but also there’s something rather romantic about following a road, IMO. The idea that the road leads somewhere. The idea that you can build something along this road and know it connects to something else.
On multiplayer servers I imagine you might see bases naturally clustering along them, plus provides an easy avenue for new players to travel out of spawn areas.
You could call it the trail biome!