The 1955 AAA Championship Car season was the final year that the American Automobile Association sanctioned top‑level open‑wheel racing in the United States, consisting of 11 championship races that began with the Indianapolis 500 on May 30 and concluded in Phoenix on November 6. Bob Sweikert emerged as the season’s dominant driver, winning the Indianapolis 500 and earning enough points through consistent finishes to claim the AAA National Championship — a remarkable feat that crowned him both the Indy 500 winner and the overall series champion in the same year. Sweikert’s performance stood out in a competitive field that included multiple race winners and strong efforts from drivers like Jimmy Bryan and Johnny Thomson.
However, the 1955 season was also marked by significant tragedies that underscored the dangers of the sport and hastened changes in American open‑wheel racing governance. During practice at the Indianapolis Motor Speedway, Manny Ayulo was killed, and in the race itself Bill Vukovich, the two‑time defending Indy 500 winner, lost his life in a multi‑car crash while leading comfortably. Later in the season, veteran driver Jack McGrath was killed in the final race at Phoenix. These losses, combined with broader safety concerns, contributed to the AAA’s decision to withdraw from competitive racing sanctioning after 1955, leading to the formation of the United States Auto Club (USAC) to take over championship racing beginning in 1956.
May 30
