For the time being, I wanted to create a circuit course that I could run on SP, so I bought EasyRoads3D and tried various things. I admit that I was a little confused at first because the various settings were written in English (I'm a Japanese speaker). However, I was able to understand the manual while translating it with Google, and was able to make things like the curbs of the circuit! I'm really moved by seeing the circuit I envisioned become a reality.
In order to actually run a car on the racing circuit in SP, there is a problem with collider, and I am currently investigating how far the collider should be subdivided. I am also facing the problem that setting the collider too finely makes it easier to get bumpy.
Despite all the problems, I'm very excited. I don't know if I can solve the problem, but if I can, I would like to create the best racing track!