The ability of IndyCar drivers to have "almost unlimited movement" at high speeds around the Las Vegas Motor Speedway was among the factors in the 15-car crash that killed driver Dan Wheldon during a race Oct. 16, the Izod IndyCar Series said Thursday.
Releasing the results of its investigation into the accident, the series indicated that the 1.5-mile speedway's high banking and the race's relatively high 34-car field were not by themselves at fault.
But the series said that although most tracks have one or two "grooves" on the racing surface that curb how much drivers can maneuver their cars, the Las Vegas oval -- combined with the design and performance of the IndyCar race cars -- gave drivers "almost unlimited movement" leading up to the fatal wreck.
"The combination of the track geometry factors allowed for relative unrestricted movement within the racing pack that had not previously been experienced," Brian Barnhart, IndyCar's president of operations, told a news conference in Indianapolis.
"This movement not only allowed for increased car-to-car contact but made it more difficult for drivers to predict the movement of other drivers around them," he said. "As a result, the opportunity for this accident was increased.
"While the accident could have occurred at any track at any time, the dynamics of the current car and the overall track geometry at the Las Vegas Motor Speedway under race conditions appear to have been causal to this accident," he said.
Wheldon, 33, had won the Indianapolis 500 for the second time this year. He was running 24th in the race at 224 mph when the chain-reaction crash started in front of him, IndyCar said.
Wheldon's car was among four that went airborne as the fiery crash unfolded, with Wheldon's car striking a catch-fence pole that caused the driver fatal head injuries, IndyCar said.
IndyCar is rolling out a new race car for 2012 that it expects will be safer, but the series recently said it would not return to the Las Vegas Motor Speedway next year as planned, citing a need for further testing there with the new car.
"I don't want to go back there if the conditions aren't right and it's not safe for our race cars," IndyCar Chief Executive Randy Bernard said Thursday.
-- Jim Peltz
Photo: Cars go airborne in the 15-car crash that killed driver Dan Wheldon on Oct. 16 at Las Vegas Motor Speedway. Credit: Barry Ambrose / Reuters