The track layout is amazing and would surely become extremely popular in the community. As it is right now it needs 2 things.
1. With high priority it needs to be optimized. Low FPS. I would assume too high poly count for many of the objects is killing frame rate. In a racing sim, well its obvious this would be a priority. All the buildings should really just not have any interior, (except for maybe the pit area which is nice) and place a texture that looks like interiors where the windows are. Less shadows to calculate, less polys..etc etc... The background map seems very detailed... while it makes sense for "drone shots" of the track, functionality wise its taking up resources.
2. Texture overhaul so things look less flat but I cant really offer much advice here other than just my perception.