Mariana pulls her pink head scarf tight down over her forehead and steps gingerly into traffic, waving her hand surreptitiously at the passing drivers to let them know she's available.
Her conservative attire makes it clear that it's not sex she's selling on the side of the road. Instead, Ms. Mariana - who like many Indonesians goes by only one name - is among the thousands of Jakarta's poor trying to make money in a trade thought to be unique to the Indonesian capital: professional hitchhiker.
"Car jockeys" such as Ms. Mariana work busy corners all over Jakarta as the city struggles to deal with gridlock that brings traffic to a standstill every morning and evening.
Hiring one or two car jockeys means a driver can ride in the slightly faster-moving carpool lanes that are restricted during morning and evening rush hour to vehicles with three or more passengers. In exchange, jockeys are usually given 10,000 or 20,000 rupiah, about $1 or $2.
"Sometimes they give me 20,000 rupiah, but if they are stingy they only give me 10,000. If they drive me for half an hour and only give me 10,000, then I get angry with them," Ms. Mariana said, adding that she usually has to spend 2,000 or 3,000 rupiah taking a bus back to her starting point after the driver drops her off across town.
The 47-year-old mother of four has worked as a jockey for the past 10 years, ever since her failing eyesight forced her from a previous job as a clothing embroiderer. At 5 p.m. on a Friday, there are two dozen jockeys on the corner she works, a side street behind Grand Indonesia Shopping Town, an upscale, eight-storey mega-mall in the centre of Jakarta.
Some are children as young as 8, and a mother with an infant strapped to her chest waves at the passing vehicles, offering two-for-the-price-of-one entry to the carpool lane. Other jockeys are young men who say they can't find a better-paying job. A 12-year-old boy named Ariyanto said he dropped out of school to make money for his family as a jockey.
The traffic in Jakarta, a city of more than 13 million people and no subway system, is legendarily bad. It's not uncommon to see 10 lanes of traffic at a dead halt as late as 9 p.m. Traffic costs the city an estimated $1.2-billion a year in wasted fuel and lost productivity, as well as health-care expenses.
While it's still possible to eventually make your way across town within a few hours, city officials predict that Jakarta will experience "total traffic" - or complete paralysis on the roads - as early as next year.
The number of cars on the road increases almost 10 per cent every year. Meanwhile, few new roads are being built, and public-transportation options are slim.
"I blame the government. The three-in-a-car rule is wrong. It would be better if the government imposed heavier taxes on new cars; people wouldn't buy so many of them," said Ahmad Sabari, a taxi driver who spends two or three hours a day at a standstill because of traffic jams. He said he has sympathy for the car jockeys, since there are few other employment opportunities for the city's poor.
While hitchhiking is considered dangerous elsewhere, Ms. Mariana said she has never had any problems despite hopping into strangers' cars four or five times a day, five days a week. While there have been some reports of sexual harassment and assaults, she said that most often the driver and jockey - having little in common - sit quietly for the duration of the ride.
"What can you do? You just sit in silence and enjoy the ride. Especially if it's a nice car," she said, smiling distractedly, her eyes fixed on the stream of drivers in black Mercedes sedans and Toyota sport utility vehicles heading home after an afternoon of shopping.
Other jockeys agree that while the carpool regulations have had the unintended effect of bringing together social classes that rarely interact, they usually find they have little to say to each other.
"The drivers don't think about us. They just give us some money and we sit there quietly," said 21-year-old Amar Binto, who works the lane behind Grand Indonesia Shopping Town. Mr. Binto said he's been working as a jockey since he was 14.
Mr. Binto and Ms. Mariana say the traffic police, who view jockeys as having helped sabotage the effectiveness of the carpool program, are a bigger worry than the drivers who pick them up. Dozens of jockeys are arrested every day for breaches of traffic regulations. They are taken to detention centres and detained for up to 90 days, a period during which they are given retraining for jobs that jockeys say don't pay as well as car-hopping.
While Indonesia's strong economic growth in recent years - its economy grew 4.5 per cent last year, despite the global downturn - has contributed to the flood of new cars on Jakarta's roads, little of that wealth has been trickling down to the country's poor. An estimated 80 million Indonesians - or one-third of all who live in the world's fourth most-populated country - live on less than $2 a day.
Working as a jockey can bring in as much as $10 or $20 a day, a windfall to those who live in Jakarta's slums. And while those affluent enough to own a vehicle curse it, the snarled traffic creates myriad other business opportunities for the city's poor, who wander among the stopped cars selling cigarettes, snacks and newspapers or playing music.
Others ask for money in exchange for information about how to cut through the surrounding neighbourhoods, or simply beg.
"When they arrest me, I tell the police that they should be arresting corrupt officials instead of a poor person like me," said Ms. Mariana, who despite being arrested twice encouraged her eldest son to also start working as a jockey.
"The problem is not just that there are too many cars here. The problem is that rich people own two or three cars, while people like me have none."