Howard ran into the path of Dixon and, as a result, the Kiwi ran over the top of him and flipped into a barrier before spinning down the track.
IndyCar DriverScott Dixon walked away from a massive crash in the 101st running of the Indianapolis 500 that left his auto split in half.
Both drivers miraculously appeared to be left unscathed by the horrifying accident which saw Dixon's vehicle left obliterated, with just the front left wheel remaining.
Race auto driver Howard was also pronounced fit after he was examined at the Indy 500. "That DW12 tub, we're thanking our lucky stars for that tub today and IndyCar and the crew always do a fantastic job, to see them running to him that quickly".
"It's tough because you just don't know which way he's going to go off the wall".
Dixon, who won the race in 2008, hoped to retain that glory.
Motorsport NZ boss Brian Budd said Scott Dixon's Indy 500 crash is up there with the biggest he has seen in the sport.
Dixon was calm and disappointed after the "wild ride".
Dixon, 36, said he was "just a little beaten up".
'I'm glad he's OK too. He also managed to walk away, and the AP reports he placed blame for the whole thing on driver Ryan Hunter-Reay. Jerry Punch. "I'm bummed for the team and for Camping World". It was just a wild ride, man. "To say that I'm upset would be an understatement".
The race was red flagged to clean the track, but both drivers escaped without serious injury.
Following a brush into the wall by Jay Howard, Dixon came around the corner and impacted the left side of Howard's off-the-pace No. 77.