One promise of ride-hailing companies like Uber and Lyft was fewer cars clogging city streets. But studies suggest the opposite: that ride-hailing companies are pulling riders off buses, subways, bicycles and their own feet and putting them in cars instead . From a report: And in what could be a new wrinkle, a service by Uber called Express Pool now is seen as directly competing with mass transit. Uber and Lyft argue that in Boston, for instance, they complement public transit by connecting riders to hubs like Logan Airport and South Station. But they have not released their own specific data about rides, leaving studies up to outside researchers. And the impact of all those cars is becoming clear, said Christo Wilson, a professor of computer science at Boston's Northeastern University, who has looked at Uber's practice of surge pricing during heavy volume. "The emerging consensus is that ride-sharing (is) increasing congestion," Wilson said. One study included surveys of 944 ride-hailing users over four weeks in late 2017 in the Boston area. Nearly six in 10 said they would have used public transportation, walked, biked or skipped the trip if the ride-hailing apps weren't available. The report also found many riders aren't using hailed rides to connect to a subway or bus line, but instead as a separate mode of transit, said Alison Felix, one of the report's authors.