So, those are the trends? Possibly reversing the trends can be possible if the cyclo's are (re-) discovered for tourism. For instance, Khmer Architecture Tours regularly have tours of architectural sites of Phnom Penh by cyclo:Cambodia's cyclo drivers pedalling towards extinction
Phnom Penh's crowded streets have become the loneliest of places for the city's cyclo drivers as peddle-power is making way for a faster pace of life in the Cambodian capital.
Increasingly lost amid a sea of cars and scooters known as motor-taxi's, these symbols of perhaps a more genteel era are struggling to remain relevant as Phnom Penh leaps towards modernity.
But that struggle appears to be a losing one, as cyclos -- pedal-driven rickshaws that were ubiquitous across what was once French Indochina -- fall out of favour and their drivers turn in greater numbers to more lucrative work.
"Modern things are coming, so out-of-date things like the cyclo will be gone," complains Khat Soeun, a wiry 43-year-old, as he squats next to his cyclo, bolting a leafspring to his broken vehicle.
On the best days Khat Soeun can make two US dollars -- half what he says he took home only a few years ago.
More often, though, he comes home with less after hours of grinding through the city's streets for just a few cents a ride.
"I cannot make as much money now as I did in the past because there are so many motorcycles and tuk-tuks," he says, referring to the large motor-driven carts that first appeared a few years ago and have begun to dominate public transport.
"We can't compete with them -- they are machines and go faster," he adds.
"Many drivers have changed from pedalling cyclos to driving motor-taxi's instead."
Roughly 2,500 cyclos plied the streets of Phnom Penh in 2004, according to a survey conducted by the Cyclo Centre, which opened in 1999 to help drivers cope with their changing world by providing English lessons, healthcare information, free haircuts and laundry facilities.
That figure was down from 10,000 reported more than a decade ago.
"But nowadays there are only some 800 to 900 cyclo drivers pedalling the streets," says Im Sambath, the centre's project director.
"We are really worried about the future of cyclos," he tells AFP.
First introduced to Cambodia in 1936, the cyclo soon became a iconic part of Phnom Penh's city-scape. They still have a small, loyal following of mostly elderly customers who are put off by the sometimes hair-raising driving of motor-taxi drivers, known locally as "motodops".
Cyclos also remain popular with foreigners seeking a slow turn around the capital's tourist spots, but the drivers remain among the poorest city residents.
"It's my family's rice bowl, what I can make allows us to survive, but just day-to-day," Khat Soeun says.
In recent years the Cyclo Centre has tried to re-ignite the love affair with cyclos, advertising them to tourists as cheap, environmentally-friendly transport and organising fund-raising "rallies" from Phnom Penh to distant provincial capitals.
"Our main target is to help the poor drivers to make a better living -- give them better information about health, urge them to quit smoking or inform them about issues like domestic violence," Im Sambath says.
The centre also offers drivers a rent-to-own plan that allows them to acquire their own second-hand cyclo for roughly 50 dollars after leasing it for about six months.
Drivers are otherwise forced to pay 50 cents a day to rent their cyclos from other operators, or borrow the 120 dollars it costs to buy a new one.
Cyclos "help poor and illiterate people feed their families," Im Sambath says, adding: "The cyclo is very important to us -- it's part of our culture."
But the number of cyclos on the road is still "decreasing every day," says 41-year-old driver Va Thorn, a regular at the centre for three years who frequently uses his welding talents to fix broken cyclos for other drivers at discounted prices.
"The cyclo is really under threat, I'm afraid they'll disappear from Cambodia," he warns.
But better roads and a middle-class preference for motor vehicles has perhaps made their disappearance inevitable, says Chuch Phoeurn, a secretary of state with the Ministry of Culture.
"Cyclos are disappearing because society is changing," he says, adding: "When people have easier ways to get around, they'll abandon cyclos."
Central Phnom Penh by cycloThis tour explores central Phnom Penh and includes Colonial buildings as well as modern, post-independence architecture. Meant to be a brief introduction to the city, the tour includes a selection of well-known buildings as well as some less obvious examples.
Traveling by cyclo is a special way of experiencing the streets and buildings of the city; we aim to enter some buildings and see others from the pavement or the cyclo. We explore the district around the old Post Office, then go south to the area south-east of the Central Market.
We start at 8.30am and aim to return after around 2.5 - 3hrs including a short drinks stop;15 adult places. Cost is $10 per person including the cyclo hire and English speaking guides. Children are free if they share a cyclo with an adult.