The rise of ride-sharing services such as Uber and Lyft has made life easier for many people, but has it also increased pollution and congestion? If enough commuters who would otherwise take a bus or train opt for an automobile ride (albeit not in the driver's seat), it could mean more cars clogging already-crowded streets.
"We find that Uber's entry increases public transit use for the average travel agency, and that the effect grows over time," write researchers Jonathan D. Hall of the University of Toronto, Craig Palsson of Utah State University, and Joseph Price of Brigham Young University.
They report that, while its effects vary considerably with the size of the city and the specific type of mass transit, introducing the service to an area increased ridership significantly over the following two years. The two types of transportation are, in most cases, complementary.
Writing in the Journal of Urban Economics, the researchers analyzed statistics from nearly 200 metropolitan areas in the United States. "We compare how transit ridership changes in cities where Uber enters, relative to changes in cities where Uber has not entered yet," they explain.
Mass-transit ridership was estimated using data from the National Transit Database, which differentiates between different modes of travel. The researchers then factored in such variables as the population of an area, its unemployment rate, and the average age, income, and education level of its residents.
"Transit ridership increases slowly after Uber enters (a metropolitan area)," they conclude. "Two years after Uber's entry, transit ridership is 5 to 8 percent higher than it would have otherwise been."
But that overall picture masks some large variations. Further analysis revealed Uber's presence reduced mass-transit ridership in smaller metropolitan areas while increasing it in larger ones. The biggest positive impact was on "small transit agencies in large cities," such as commuter rail lines.
That makes sense: The ability to take an Uber to the station may make train travel more appealing. You may even find you don't need a car (or a second car), which could save a lot of money.
In addition, the researchers note, many commuters are hesitant to use mass transit services—especially those that run on limited, set schedules—because they fear they may have to get home from work quickly, perhaps to deal with a sick child. Uber means they can easily do so in the case of such an emergency.
The researchers found Uber coming into a market has a negative effect on bus ridership, likely because higher-income people who were taking the bus to work suddenly had an alternative that didn't involve driving. But the service's net effect is more people taking public transportation.
Now, it's possible that Uber could ultimately increase traffic congestion "by either increasing the total trips taken, or by flooding the streets with Uber drivers looking for a fare," the researchers concede. But so far, the flexibility it provides is giving more people an incentive to leave their cars at home.