Prior to the third free practice for the United States Grand Prix the FIA has changed the regulations for the weekend. Race director Michael Masi decided after the practice sessions on Friday that a clarification on track limits was in order.
The existing track limits at the Circuit of the Americas are at the exit of Turn 9 and Turn 19. The FIA added a new point on Saturday morning: the apex of Turn 6.
FIA adds track limit after Friday at COTA
The new track limit means that drivers cannot lose contact with the red/white kerbs. If they go over the kerbs with all four wheels it is considered an overrun and the time will be deleted.