PHOTOS: Indianapolis 500 through the years

Juan Pablo Montoya, of Colombia, celebrates after winning the 99th running of the Indianapolis 500 auto race at Indianapolis Motor Speedway in Indianapolis, Sunday, May 24, 2015. (AP Photo/Darron Cummings)

Pace car driver Harry Hartz pulls aside in the Studebaker as the racers start into the first lap of the Memorial Day 500-mile auto race in Indianapolis, Ind. on May 20, 1940. (AP Photo)

Pat Flaherty, Glendale, Ca., poses in his Granatelli Sabourin Special after qualifying for the Indy 500 at the Indianapolis Motor Speedway in Indianapolis, Ind., May 13, 1950. (AP Photo)

Mario Andretti has a big smile and is wearing a wreath of flowers in Victory Lane after he won the 53rd Annual Indianapolis 500-mile speedway race in Indianapolis May 30, 1969. (AP Photo)

With a loving pat on his neck, Ma Unser, as she is called, congratulates her son, Al Unser, on his victory on May 30, 1970 in the Indianapolis 500-mile speedway race. (AP Photo)

Bobby Unser waves as he cautiously drives his Eagle-Turbo Offy across the finish line to win the rain-shortened Indy 500-mile race at Indianapolis, Ind., Sunday, May 25, 1975. (AP Photo)

Johnny Rutherford cheers with his right hand as he crosses the checkered flag in his Pennzoil Chaparral after completing the 200th lap of the Indianapolis 500 on May 25, 1980. (AP Photo)

Danny Sullivan of Louisville, Ky., sits on his championship race car during the traditional photographs of the Indianapolis 500 winner on the finish line on May 27, 1985. (AP Photo/Michael Conroy)

Race driver Arie Luyendyk waves to the crowd after he won his first Indianapolis Motor Speedway 500 on Sunday, May 27, 1990. (AP Photo/AL Behrman)

The car of Stan Fox, top, breaks apart as it hits the wall following a first-turn collision with Eddie Cheever on the first lap of the 79th Indianapolis 500, Sunday, May 28, 1995. (AP Photo/Martin Seppala)

Car owner Chip Ganassi, left, celebrates with Dario Franchitti, of Scotland, after they won the Indianapolis 500 auto race at Indianapolis Motor Speedway on May 30, 2010. (AP Photo/Darron Cummings, File)

IndyCar driver Dan Wheldon, of England, poses with his family after winning the Indianapolis 500 race on May 30, 2011. Wheldon died in October 2011 in a fiery wreck in Las Vegas. ((AP Photo/Michael Conroy, File)

IndyCar driver Dario Franchitti of Scotland reacts after winning the running of the 96th Indianapolis 500 auto race at the Indianapolis Motor Speedway on May 27, 2012. (AP Photo/Darron Cummings)

Tony Kanaan, of Brazil, poses with his wife Lauren in the winner wreath after winning the Indianapolis 500 auto race at the Indianapolis Motor Speedway on May 27, 2013. (AP Photo/Michael Conroy)

Ryan Hunter-Reay celebrates winning the 98th running of the Indianapolis 500 IndyCar auto race at the Indianapolis Motor Speedway in Indianapolis on May 25, 2014. (AP Photo/AJ Mast)

Fans with painted faces gather for a photo during an autograph session for the Indianapolis 500 auto race at Indianapolis Motor Speedway in Indianapolis on May 23, 2015. (AP Photo/Darron Cummings)

Ryan Hunter-Reay, left, Takuma Sato, of Japan, center, and Jack Hawksworth, of England, signs helmets before the drivers meeting for the Indianapolis 500 on May 23, 2015. (AP Photo/Darron Cummings)

Fans gather for a concert in the infield before the 99th running of the Indianapolis 500 auto race at Indianapolis Motor Speedway in Indianapolis on May 24, 2015. (AP Photo/AJ Mast)

Scott Dixon, of New Zealand, leads the field to start the 99th running of the Indianapolis 500 auto race at Indianapolis Motor Speedway in Indianapolis on May 24, 2015. (AP Photo/AJ Mast)

Simon Pagenaud, of France, (22) and Alex Tagliani, of Canada, (48) drive under the crashed car of Ed Carpenter in the first turn during the Indianapolis 500 on May 24, 2015. (AP Photo/AJ Mast)