"It was a dark pick-up - that's all I can remember - but moving directly on to the shoulder and speeding up. That's something that does haunt me," Ashill told ABC 6 WSYX Columbus.
He said there was no way the driver could have mistaken him for anything other than a runner.
"I always wear colourful clothing so it's not as though I look like a wild deer."
He was now on the slow road to recovery in an Ohio State University Hospital with a broken leg, pelvis and internal injuries. He has had five operations to repair the wounds and is not expected to be able to walk again for several months.
Despite his ordeal Ashill was grateful to have survived and determined to run again.
"I'm lucky. I'm alive. I have my life. Somebody else may not have been so fortunate," he told ABC 6 WSYX Columbus.
He appealed to the driver of the mystery vehicle to come forward.
"Own what you have done and that will help everybody concerned. That will help me and that will help you," he said.
Police investigating the hit-and-run still have no suspects.
Ashill was running across America to raise funds to support families affected by pulmonary fibrosis.
That has gone on hold but two online fundraising pages in New Zealand and the United States have been set up to help meet the staggering $500,000 medical and rehabilitation bill Ashill faces over the next six months.
https://givealittle.co.nz/cause/gettingnickbackonhisfeet?_ga=2.236583554.2055980389.1503692198-1372704403.1499664363
https://www.gofundme.com/get-nick-back-on-his-feet
https://givealittle.co.nz/cause/gettingnickbackonhisfeet?_ga=2.236583554.2055980389.1503692198-1372704403.1499664363