Ride-sharing services like Uber and Lyft are cutting into public transit use in cities like Chicago, according to a new study.The study by the University of California-Davis Institute of Transportation Studies found that after adopting ride-sharing services, there was a net 6 percent decline in transit based on of survey respondents’ changes in travel behavior.

“Data across the country has made it pretty clear that there are aspects of ride-hailing that are directly competitive with transit,” said Kyle Whitehead, government relations director with the Active Transportation Alliance, which advocates for transit, bicyclists and pedestrians. The study concluded that ride-sharing is likely to contribute to growth in vehicle miles traveled in major cities, which means more traffic on the streets.