Inside The Indy 500: Racing Flag Colors And Meanings
Checkered Flag: Signifies the end of the practice session, qualification attempt or race. The race leader is declared the winner.
Green Flag: Signals the start of the practice session, qualification attempt or race and all restarts after a caution or red-flag period.
Yellow Flag: The “caution flag,” signals hazardous conditions on the track, and cars must slow immediately, maintain position and yield to track safety vehicles until the green flag is displayed. During a qualification session, a qualification attempt is halted.
White Flag: Displayed when the leader starts the final lap of the race. During qualifications, signals that driver has started final lap of qualification attempt.
Royal Blue Flag with Diagonal Yellow Stripe: The “passing flag,” signals slower cars to yield to faster traffic.
Red Flag: Signals that the race stops immediately, regardless of position of cars on the track.
Black Flag: Directs a driver to proceed to the pits on the next lap and to consult with race officials.
Black Flag with White Cross: Officials have ceased scoring the car until further notice.
Alternating Red and Yellow Striping: Signals that oil, water or some other substance has made track surface slippery.
Sources: Indy Racing League Media Relations, Indy Racing League Technical Department, IndyCar Series race teams, Firestone, Honda, Indianapolis Motor Speedway Hall of Fame Museum