Thanks, and it was! The mesh itself is pretty simple, it's basically a line renderer that I add to every time my starting point (what you actually control) gets far enough away. I also record this info for the cars so they can sample it on a delay to more smoothly follow an ideal spoth on the path that you carve out.
The trickiest part of it was collisions. I tried just creating a mesh collider but this gave me all kinds of headaches due to it being concave when you go up and down, so instead it's a series of box colliders. Since they're boxes, the cars are more hovercrafts to avoid bouncing and they have to take a few samples of the ground to figure out what direction "up" is. This is also one of the reasons the road is so short, I was worried about creating too many colliders and crashing the game and didn't have time to figure out what a realistic limit would be.