This is how quickly transportation has changed in urban America. In July 2010, a service called UberCab went live in San Francisco—that's fewer than eight years ago. Washington, DC's Capital Bikeshare, the country's largest bike-sharing program, really got off the ground in 2010. Austin became the first US city to host car-sharing service Car2Go a few months into the same year. Lyft launched in SF in June 2012.

That's a ton more travel options in a short time, most of them enabled by the explosion of the smartphone and fostered somewhere in the Bay Area. Some have indubitably made it easier, cheaper, and safer for residents to travel through dense cities. But for city governments that feel responsible for getting all their residents around, the sudden burst of diversity has confused the whole picture.

Are people moving away from public transit, putting a small but significant dent in already dwindling public coffers? Are they taking more car trips overall, creating unbearable congestion? Are they selling their personal cars, opening up valuable curbside parking spots for delivery vans and bike-sharing stations? Transportation researchers, the sorts of folks who study cities and try to sort out how mobility services have transformed urban streets, are racing, tongues a-lolling, to catch up.

Now, hope: A new report shines a touch more light on how traveling around cities works today. Researchers at the Shared Use Mobility Center pored over data provided by an unnamed ride-hailing company—maybe Uber or Lyft, staying anonymous for competitive reasons—plus a 2015 survey of 4,500 car-share, bike-share, and transit users, plus newly released numbers from four transit agencies' surveys of their own riders. Their verdict? The picture is still blurry, and definitely very complicated.