circuit. This became evident at the 2001 Firestone Firehawk 600, when drivers experienced vertigo-like symptoms, and the race was cancelled for safety reasons. As of 2020, the IndyCar Series has only one race remaining at a high-banked intermediate track (Texas). These tracks began to be removed from the Indy car schedule in the late-2000s and early-2010s due to low crowds and serious crashes, including the fatal accident involving Dan Wheldon at Las Vegas in 2011. Superspeedway Originally a superspeedway was an oval race track with a length of one mile or more. Since the introduction of the intermediate oval, Superspeedway is an oval race course of 2 miles or longer. There are six active superspeedways in the United States, the most famous being Indianapolis Motor Speedway and Daytona International Speedway, both long. These tracks were built in 1909 and 1959 respectively. Indianapolis Motor Speedway was built as a facility for the automotive industry to conduct research and development. Daytona International Speedway was built as a replacement for the Daytona Beach Road Course, which combined the town's main street and its famous beach. Daytona hosts the Daytona 500, NASCAR's most prestigious race, while the Indianapolis Motor Speedway is home to the Indianapolis 500 and the Brickyard 400. The longest superspeedway is the Talladega Superspeedway in Talladega, Alabama. Built in 1969, it is long, and holds the current record for fastest speed in a stock car, lapping at an average of and reaching at the end of the backstretch. Daytona and Talladega are the pinnacle of stock car superspeedway racing, where restrictor plates are mandated by the sport's ruling body to reduce the high speeds accommodated by their steep banking since 1988. Other superspeedways used by NASCAR include the Michigan International Speedway (2.0 miles), Auto Club Speedway (known as California Speedway prior to February 2008) (2.0 miles), and Pocono Raceway (2.5 miles). Auto Club Speedway and Michigan are often considered intermediate tracks by NASCAR due to their similarities with 1.5-mile tracks, while Pocono and Indianapolis are sometimes classified separately, as they are the only long, flat tracks on the schedule. Auto Club Speedway, which joined Indianapolis, Michigan and Pocono as the one of four superspeedways used in the Verizon IndyCar Series, was the site of Gil de Ferran's qualifying lap of in the CART FedEx Championship Series in 2000, the fastest qualifying lap recorded at an official race meeting. Due to the