Jimmie Johnson believes IndyCar should abandon racing on ovals and instead focus on road and street courses following the accident that claimed the life of Dan Wheldon in the series finale at Las Vegas last Sunday.
Speaking at Charlotte Motor Speedway during a NASCAR test, the five-time Sprint Cup champion also expressed his sorrow at the death of Wheldon in the 15-car pile-up.
"[I'm] extremely sad to see what took place yesterday in the [IndyCar] race," said Johnson. "This racing community is a small community. It impacted me dramatically yesterday as I sat and watched all of it.
"I sat there with my mouth wide open at the carnage that took place over there in turns 1 and 2. I was glued to the television for a couple of hours watching the red flag and what unfolded.
"I just couldn't believe that it took Dan's life. There were three other cars that took off the ground and I was so thankful that Will Power and a couple of other guys that got upside down weren't fatally injured as well."
Johnson revealed that he had previously dreamed of competing at the Indianapolis 500, but that he had given up any such thoughts since becoming a father, due to the risks involved.
He strongly believes that IndyCars should not race on ovals in the future due to the potential for cars to become airborne, as happened at Las Vegas.
"There's a racer in me that wants to [run the Indy 500], but I know how dangerous those cars are and yesterday was proof to the danger of those vehicles on ovals," added Johnson.
"I think it really boils down to the fact that - I guess if you really look at the big picture, why we run restrictor plates [in NASCAR], is so the cars stay on the ground and it doesn't matter the type of race car, if it's off the ground, you can't control it in an accident. And those cars are going so fast that get airborne frequently on ovals.
"I wouldn't run them on ovals. There's no need to. Those cars are fantastic for street circuits, for road courses. The ovals at those speeds, you can't control the vehicle when it's off the ground and there's very little crumple zone around the driver, and then obviously it's an open cockpit and then you add open wheels - you're just creating situations to get the car off the ground at a high rate of speed."
"I hate that this tragedy took place but hopefully they [IndyCar organisers] can learn some things from it and make those cars safer on ovals somehow. I don't know how. I have a lot of friends that race in that series. I rather see them on street circuits and road coursed, not ovals."
Johnson believes last Sunday's scenario at Vegas did not arise particularly due to the characteristics of the track, but more because of the nature of side-by-side racing at very high speeds with open-wheeled cars.
"It's not just Vegas," said Johnson. "You watch those cars at Kentucky, even Indy. I can't imagine running around Richmond wide-open and really racing with someone like they do. You look at all the ovals, even Milwaukee.
"They're flying around Milwaukee and New Hampshire at places that I can't even imagine I could drive that fast and it's cool to see that, but those vehicles have a lot of things that lead to getting them off the ground. That's the big thing to focus on. Once the car gets airborne, doesn't matter the type of car, you can't control it in a crash."
Next weekend's Sprint Cup race takes place at Talladega, where cars run flat-out for the whole lap while racing in packs with bumper-to-bumper contact at more than 200mph. However, speeds are limited by restrictor plates that were implemented in the late 1980s on safety grounds. Roof flaps and other devices also help cars reduce speed and remain on the track when out of control at high speeds.
Johnson believes NASCAR has done plenty of work to try to keep cars from lifting from the track and although there have been occasional flips recently, he believes drivers are not exposed at such high risks as IndyCar racers on ovals.
"We know what the risks are but I think the risk factor when you drive on an open-wheeled car is multiplied by 10," said Johnson. "There's got to be a big number that it's multiplied by. Yes, that risk exists, but I feel like NASCAR has worked hard to keep speeds down. We have devices on the vehicle that keep them on the ground. Yes, we have seen a couple of airborne lately, but we don't have those types of crashes.
"I'm not saying the perfect storm couldn't take place and we couldn't see a couple get off the ground, but Talladega has its risks and I know that but I just don't see the cars having the same issues. We have the potential, but I just don't see the chances anywhere in the ballpark of those open-wheeled cars."