One of NASCAR’s most decorated drivers says he couldn’t commit to a full IndyCar Series campaign this year for fear of crashing on a speedway.

Johnson is in the midst of his first season in the IndyCar Series, racing exclusively on road courses and street circuits while Tony Kanaan contests the oval events in his place.

While he hasn’t driven an IndyCar at any of the speedways yet, Johnson has been present on the sidelines either as an interested spectator or commentator.

Speaking in the lead up to this weekend’s Big Machine Music City Grand Prix on the streets of Nashville, Johnson detailed his hesitancy to race on an oval.

However, as he watches on, the 45-year-old is beginning to warm to the idea.

So much so that the seven-time NASCAR Cup Series champion is targeting an oval test later this month at Homestead-Miami Speedway.

“Ultimately, I’m trying to understand the safety level of the IndyCar on the ovals,” Johnson explained.

“That’s really been my fear, from being a fan and watching from afar and watching my friends race on ovals. That’s the part that has worried me.

“As a father of two, and a deal I made with my wife a long time ago about the Indy 500, I’ve kind of watched the ovals and really never thought that I could be out there.

“But then anticipating this year as a television commentator, being around the sport all season like I have, seeing a few big crashes at the Brickyard and speaking to the drivers after, I’m becoming much more comfortable with the ovals and with the crash dynamics that take place, with softer walls, the halo, the aeroscreen, the top of the car, and I’m at a point now where in a funny way I’m willing to go hit a wall.

“And in some ways it’s like, I’m not going to know unless I really hammer a wall how much it hurts. The folks at [Chip] Ganassi [Racing] are going to hate to read this wherever it comes out, but yes, I need to go make laps and I need to understand what that experience is like, but ultimately I’m just trying to understand the safety level of the car, and as I get more comfortable with that, my participation on ovals will increase.”

Team-mates Scott Dixon and Alex Palou have both had sizable crashes at Indianapolis Motor Speedway.

Notably, Palou crashed in the first practice at this year’s Indianapolis 500, something Johnson said helped him understand how the car behaves during a crash.

“I think watching the Indy 500 this year and seeing Alex’s huge crash that he had in practice, he was fine,” said Johnson.

“He walked away. That was a big checkmark for me, like okay, wall, car, that speed, that all worked well.

“What’s tricky is climbing wheels, and we know that. The less pack racing has been directionally correct for me in considering running on ovals.”

Nevertheless, there is a desire for Johnson to make an Indianapolis 500 cameo in the future.

While the #48 pilot has only once cracked the top 20 this year, Johnson is curious to know how he would fare on the ovals given his prolific experience in NASCAR.

“That’s the carrot that’s hanging out in front of me,” he said.

“I’m running around the back of the pack now on street and road courses, and thinking, ‘Man, if I was on an oval, where would I be?’

“That’s the balance I’m fighting with right now, the risk versus reward during an oval race.”

Johnson will be back in action this weekend at the Nashville Street Circuit across August 7-9 (AEST).