The cyclo has been a distinctive feature of Phnom Penh's streets for 70 years, stretching back to the days when Cambodia was a French colony. But this form of transport has begun to fade away.
New York has its yellow cab. London has its red bus. But Phnom Penh has its cyclo - a three-wheeled bicycle with the driver perched on high above the rear wheel, and the passengers in a bucket seat slung between the two front wheels.
This iconic vehicle has proved a comfortable - if slow - way of getting around Cambodia's capital for the best part of a century. But that is changing.
In the past decade the number of cyclos on the city's streets has declined sharply. Im Sambath heads the Cyclo Conservation and Career Association, which looks out for the interests of the drivers.
"Now we have around 1,300 cyclo drivers in Phnom Penh. But from our survey, in 1999 [we had] around 9,000 cyclos," he notes.
He estimates in five years, there could be only 500 or 600 cyclos left.
Im Sambath says there are a number of reasons for the decline - from the changing travel habits of the Phnom Penh's citizens to the rise of the tuktuk - a motorized rickshaw.
"And tuktuks are quicker than cyclo, and can take their equipment from the market or something else easier than a cyclo," he says.
Cyclo drivers pay around 25 cents a month to join the Cyclo Association. The hundred or so members get washing facilities, HIV/AIDS education and other health benefits.
But most valuably, they get access to foreign tourists. Im Sambath says as local demand drops, foreign tourists are the future.
The association works with travel agents to arrange cyclo tours of Phnom Penh, in which tourists are pedaled around this flat city's compact array of sights.
The association's oldest cyclo driver is 75-year-old Oum Sok. He has been pedaling the city's streets since he was 18.
Like most drivers, Oum Sok is from rural Cambodia where there is little work. Like them, he parks his cyclo on the sidewalk each night in a gaggle of other drivers, and sleeps in the bucket seat.
Ferrying tourists provides a reasonable living. Oum Sok earns $8 from the association for a day's work, plus any tips.
But it is no fortune. While waiting outside the city's National Museum for the tourists to emerge, he talks about the changes in his half century of pedaling people around Phnom Penh.
He says when he was young, he could earn a lot, but now everything is expensive. Another thing is that the customers do not want to take a cyclo with an old man like him driving.
But he acknowledges his age can prove a benefit. In a culture that respects age, Cambodians tend to tip better than the tourists.
But tourists may be the way forward for most cyclo drivers.
Australian Margie Edmonds has just spent the morning as part of a cyclo tour with about 20 tourists.
"Well I just thought it was the most amazing way to do it," she says. "Their [the drivers] understanding of the traffic, and their kindness. It was one of the best experiences I've had in Asia. Great fun, very safe and very comfortable vehicles too."
Back at the association, Im Sambath says the cyclo is down, but not out.
He is optimistic that targeting the two million tourists visiting Cambodia each year will allow the dwindling stock of drivers to provide for their families in the provinces.