A Wellington man left for dead after he was hit by a ute during a run across America has finally crossed the finish line - five years later.

Nick Ashill was greeted with a "substantial" hot dog at his finishing line on Coney Island, which he "inhaled" after his mammoth effort completing the run.

Ashill was on day 81 of a run across America to raise awareness and funds for pulmonary fibrosis when he was struck in what appeared to be a deliberate hit and run.

He was on the phone to his wife and two daughters on August 2, 2017 when he saw the dark-coloured ute approaching.

He watched as the ute crossed two lanes, before speeding up and veering on to the shoulder of the road to hit him.

"In that split second I knew I was going to be hit, so attempted to jump out of the way across the small metal railing, but I got slammed on the side," he told the Herald.

Ashill was flung into a ditch where he was not visible from the road. If it hadn't been for his family hearing what happened, he likely would have died.

Nick Ashill stands on the Santa Monica Pier at the end of Route 66 in 2017, about to begin his run. Photo / Supplied

It has taken 16 surgeries and nearly five years to recover from the huge trauma his body suffered, which included open fractures, a shattered pelvis, and internal injuries from the bone fragments.

Even from his early days in the hospital, Ashill was already planning to return and finish the run. In May he flew back and picked up where he left off, joined by numerous rescuers and health professionals, including three surgeons who saved his life.

Today, Ashill finally crossed the finish line about 3.30pm New York time.

Speaking to the Herald shortly afterwards, he said it already seemed "years ago" that he finished the run.

The feeling of finishing hadn't sunk in yet, partly because the emotions he had when starting the run in 2017 were so different to the emotions he had now.

Kiwi ultra-marathon runner Nick Ashill in hospital after being struck by a ute and left for dead on a US highway. Photo / Supplied

"It feels really good. I'm looking forward to a break from running for a wee while," he said.

The Victoria University of Wellington marketing professor said the first couple of days after resuming the run were smooth sailing, but challenges set in such as infected blisters and tackling large hills in Pennsylvania.

Ashill, who was running to raise funds and awareness after his mother died of pulmonary fibrosis, said he had to dig deep and think often of his mother as he crossed the hills.

The night before he was due to pass the spot where he had been injured in the hit and run, Ashill and a support team went to visit the site.

"I had some words there. I won't repeat what I said because they were colourful words," he said.

The next day Ashill was able to run past the site with ease, having already said his piece.

"I didn't even look at it," he said.

One highlight of the run was spotting a black bear down a driveway. Photo / Supplied

The rest of the run involved the occasional interaction with rattlesnakes, and a highlight was seeing a black bear down somebody's driveway.

Entering New York - having started the run on the other side of the country at Santa Monica Pier - was "pretty special".

Now Ashill is looking forward to some time to relax, and will fly home to New Zealand in about a week.

As of this morning he was about 90 per cent of the way to his goal of raising $10,000 for the Asthma and Respiratory Foundation.