Problem with the overlapping of my model, how to fix this?

I think here it would be better to use another method, also overlap events + fast movements is not a good combo, you could use instead a line trace pointing down and detect if it’s hitting either the road or the dirt and change the variable with that.

Another point is having the need for a mesh with precise collision and the exact same shape of your track is not the best workflow, it’ll bring issues sooner or later.