Chances are if you're driving across the Nullarbor linking Western Australia and South Australia you'll see cyclists making the arduous trek on two wheels.
Out in the elements on one of the most isolated highways in the world, most of the cyclists are young and fit, making the journey for charities or the record books.
For New Zealanders Del and Cindy Henley, the trek is about taking time out from their retirement village Possum Bourne at Pukekohe, south of Auckland.
Both are a spritely 81 years old.
The pair are on their second Nullarbor pilgrimage, but it's not their longest Australian bike ride.
"We took up cycling when we were 70," Mr Henley said.
"We were not doing much, and it was a challenge at our age getting on a road bike.
"Now we've got the road bike and lycra – the lot," Mrs Henley said.
Up for a challenge
Mr Henley completed his first road cycle as a fundraiser for the local bowls club, which took him on a 2,000 kilometre cycle to the top of New Zealand's North Island at Cape Reinga.
"Then I thought 'It's finished. I wonder if there's something else I could do?'," Mr Henley said.
He looked across the Tasman Sea to the huge expanse of Australia and thought the continent would be ideal for long-distance cycling.
This epic journey from Perth in Western Australia to the Gold Coast on the eastern seaboard will mark the couple's sixth Australian road trip, and will be a return to the Nullarbor Plain, which they crossed in their first trip in 2012.
"I was a bit nervous in approaching Cindy about coming for a bike ride so I said, 'Would you like to go for a little bit of a bike ride? Across the Nullarbor Plain?',"
"And so we did that for a start and then it just continued and we did the rest of Australia as well."
Mrs Henley said she took up cycling because she worried about her husband's safety and wanted to be with him.
She's still cycling along with him despite a serious crash in 2018 that landed her in hospital with a broken shoulder and cuts to her face.
It was on the home stretch of a massive 6,000 km ride from Cairns to Perth that she hit a pothole that jackknifed the bike's trailer and sent her sprawling to the bitumen.
But it has not stopped her enthusiasm for riding.
"I was busy looking at all the wildflowers that were growing by the wayside and I didn't notice that I'd hit a pothole," Mrs Henley said.
Battling headwinds
The pair enjoy the planning of their trips as much as the satisfaction of reaching their destination.
"We know we're not youngsters anymore so physically, 'could we manage to do that?' was part of the challenge," Mr Henley said.
"Mentally, too, it's a challenge putting up with [and being] out of your comfort zone, really badly, sleeping on the dirt in a tent when it's freezing cold."
This trip has been a challenge with few comfortable beds available for recuperation.
Much of the accommodation at roadhouses had been booked out across the Nullarbor, leaving them to camp in their tent for large chunks of the journey.
"We chose Perth [as a starting point] because we were hoping for a tailwind all the way across the Nullarbor," Mr Henley said.
"We'd read that it was prevalent at this time of year — wrong."
The couple are cycling 50 to 60 kilometres a day, often battling headwind.
Mrs Henley said the lack of a comfortable room and bed had been the hardest part of the trip.
"It was -4 Celsius the other day when we woke up," she said.
Mr Henley said the trip was more physically challenging as 80 year olds.
"It hurts, and it's slow and everything's a pain and standing up straight and bending down and getting in and out of a tent and squatting when you go to the toilet," he said.
"We can do it but we do it perhaps not as easily, not quite as easily," Mrs Henley said.
"So we have to take more stops now to recover from the last little bit of the last hill.
"And it's taking a little longer to get to where we're going."
The couple are no strangers to challenges, having spent three years in the 1970s living off grid on an island off New Zealand where they spent 90 per cent of their day fishing and gathering food with their three children.
Preparation is key
Mr Henley said he enjoyed the preparation for a trip and the daily planning when on the road.
"Taking all your food and trying to work out how much food you're going to need, what you could afford to carry and what the weight is, and what if you have an accident and how you're going to (cope). So there's a lot of what-ifs that you've got to work through," he said.
"It's just not flippant. We've probably spent six, seven months just planning stop by stop, by stop, by stop."
The Henleys said their children, "think we're mad" but would be quietly proud of their adventures.
While they are not sure if this will be their last cycling trip to Australia, they say they've enjoyed the open road and the stars of the Nullarbor night sky.
"You could spend your life cycling around Australia and never see half of it, well never see most of it," Mrs Henley said.