On March 18, they drove an average of 3 hours and 35 minutes, down 39 percent from 5 hours and 50 minutes on a typical Wednesday. They also covered an average of 48 miles, a 32 percent drop from 71 miles.

“This is so massive and so sudden, it’s a shock to the system,” said Eran Shir, Nexar’s co-founder and chief executive officer, who has seen similar drops in other cities. “We’ve never seen anything like that.”

Uber and Lyft declined to release their ride numbers in New York.

But Uber’s chief executive officer, Dara Khosrowshahi, said in a March 19 call with investors that bookings for rides in Seattle and other hard-hit areas had fallen by as much as 60 to 70 percent.

New York City has about 200,000 for-hire drivers licensed by the Taxi and Limousine Commission. The drivers are issued a universal license that allows them to drive yellow taxis, which are capped at nearly 13,600 by the city, and for ride-app services.

The commission, which tracks taxi ridership numbers, has only collected data through January, well before coronavirus reached New York.

Michael Woloz, a longtime taxi industry consultant, said taxi garages had stayed open through some of the city’s worst crises — including the Sept. 11 terror attacks and Hurricane Sandy — but were reeling from the coronavirus fallout.

Many garages, he said, were taking extraordinary steps to get their taxis out on the streets, including reducing leasing fees for drivers by as much as two-thirds.