He recalls looking to his right at the bottom of Birkdale Rd to make sure the way was clear of any traffic to which he had to give way.
The next thing he knew, he was on the ground after being hit by a car from his left, calling out for someone to get its number while concerned about being run over by other vehicles.
"But she stopped anyway," he said of the driver. "I can't recollect seeing her, I just heard her voice saying 'he hit me', which I thought was a strange thing to say, because she hit me."
Because his hands were uninjured, and he was aware a bus needed to get through the roundabout, he started trying to move himself out of the road before an ambulance arrived.
"But as soon as I tried to get up, I felt my thigh."
Mr Barfoot said he didn't hold any grudge against the driver, but wished Auckland motorists in general would be as careful and polite as those he came across in France last year, when he won a world triathlon title for his age group.
"When I cycle in France, drivers are so polite. They don't try to overtake you on a narrow road. French drivers tend to be more patient."
Doctors and nurses at the hospital had remarked on how healthy he was for his age, while remaining guarded about how long he would remain incapacitated.
That has left him using Google to try to estimate his recovery time.
"They're very cagey about how long it will take," he said.
"The surgeon said they had just spent $30,000 on a new hip, that it would be silly to go and smash it, and it will never be as good as your own hip. I know lots of people who swim, cycle and walk well on artificial hips but I haven't noticed any setting any records."