dynamic accumulation of rubber on the track, is it true?

[El Ferno]

Both iRacing and Project Cars feature a full and dynamic simulation of rubber on the track, which accumulates as cars pass over it, enhancing grip in the curves and improving the track's visually. Is this level of detail present in Forza Motorsport??, or is it merely another "built from the ground ahh down" bullyiet?

[Jamma003]

It does seem to do it, the track gets darker over time, personally I dont notice the grip increase. I also suspect its just a specific texture overlaid onto the track that is not factoring in where cars actually drive.