No. Back when the cfg hacks allowed to intensify the race line I saw it update when a car drove over it. If it drove the same line it got stronger, if it drove a different line the rubber got weaker and moved a little towards the different line.
The rubber line is also used to determine if a track is rallycross or not. If a certain % of the rubber line lies on dirt, the track is considered a rallyX one. This is also the reason why certain road tracks with a offroad layout on them become rallyX tracks and won't give out the "rally tyres on road track" warning anymore, or on the contrary, when you remove the layout all players will get a "road tyres on rallyx track" warning until the rubber line is moved back onto the track enough.