Each person fixes their own car. Track isn't responsible.
We had a member in a street session 2 years ago at PIR. (not even wheel to wheel racing, just out driving hot laps).
He was middle on the bank of the oval turn and the Boxter in front of him was high on the oval. Pit lane in at the bottom of the track (inside of the track).
People going to the pits are supposed to come into the banked oval turn low so they can enter the pits without crossing traffic.
Boxter guy decides way late in the turn he wants to get into the pits - right now- and instead of making another lap so he could make a safe entry to the pits, goes from high on the bank, across the track and directly in front of the Viper. Viper impacts the Boster driver door hard. Boster driver Airlifted out. Both cars totaled. Each driver takes care of his own damage, although the Viper owner tried to get some compensation.
In the case of last weekend, each owner pays for their own fix.
Review of in car cameras on other race cars and discussions with drivers both involved and not involved led to decision that while not intentional, the driving of the truck caused the incidents at the beginning and near end of the race.