Now, Mr. Kumanovic, 34 years old, is a driver for Uber Technologies Inc., picking up passengers in his 2011 silver Dodge minivan for the car service whose volatile increase in New York faced the risk of a temporary limitation before city officials backed down.

He is among the Uber motorists who often drive around Manhattan waiting for the business’s program to send them to their next fare-a practice that city officials worry is slowing down traffic on already-congested Manhattan streets.

The business counts about 23,000 drivers in New York City, plus about 6,000 drivers of yellow and green cabs who draw hails through its uberT attribute.

T are about 52,600 drivers licensed to drive yellow cabs, according to the city’s Taxi and Limousine Commission.

In the runup to some City Council vote on a proposed limitation on new for-hire vehicles that was eventually put off, the New York Taxi Workers Alliance held a rally highlighting what members see as Uber’s menace to drivers’ steady jobs.

Josh Mohrer, the business ‘s general manager in New York, said Uber wouldn’t add new drivers if their pay slips.