Now a new report finds that ride-hailing cars are often driving on the city’s busiest streets with no passengers — in effect, creating congestion without any benefits. The report by Bruce Schaller, a former city transportation official, found that more than a third of ride-hailing cars and yellow taxis are empty at any given time during weekdays in Manhattan’s main business district.

The ride-hailing cars average 11 minutes of unoccupied time — compared with eight minutes for yellow taxis — in between dropping off one passenger and picking up another, according to the report.