Uber has become hugely popular in New York, and its trips outpaced yellow taxis for the first time last year. There are about 65,000 vehicles affiliated with Uber in the city, which provide more than 400,000 trips per day, according to the Taxi and Limousine Commission. Lyft, its main rival, tallies about 112,000 trips per day. City law caps the number of yellow taxis at about 13,500; they typically make about 300,000 trips each day.

New Yorkers get cheap rides in nice vehicles — and a respite from the failing subway — while Uber is moving toward an initial public offering next year at a value of $48 billion. But many of the drivers who New Yorkers and Uber executives rely on are feeling hopeless.

Drivers are trapped in predatory car loans. The money they make from each trip is relatively paltry after fees, like sales tax, are deducted and after Uber takes its cut of more than 20 percent.

Pedro Acosta began driving for Uber shortly after the service arrived in New York in 2011. At first, he made a good living. Uber enticed drivers, promising they would make $5,000 during their first month. But then the app started reducing its rates.

“They dropped the price so much,” Mr. Acosta said at his apartment in East New York, Brooklyn, the day after he worked an 11-hour shift. “We have to work so many hours.”

Mr. Acosta made 4,457 trips for Uber last year, or more than 85 rides each week. He made about $30,000 after expenses, according to his tax returns, an amount that he said was difficult to live off in an increasingly expensive city. He has six children, and his wife works giving massages and facials.