New Study: “What Does Ridesharing Replace?”

WASHINGTON, DC—What transportation modes do ridesharing apps like Uber and Lyft replace? A new Resources for the Future (RFF) working paper by Benjamin Leard, a fellow at RFF, and Jianwei Xing, an assistant professor at Peking University, investigates how the availability of ridesharing affects traffic, air pollution, and public transit use.

An accompanying blog post breaks down the study's findings, from environmental repercussions to implications for public policy. 

The authors use data from a large sample of metropolitan areas to track how the option of ridesharing impacts travelers’ transportation choices, and they simulate how people would have traveled if ridesharing were unavailable. Leard and Xing estimate the additional vehicle miles traveled and greenhouse gas emissions ridesharing has caused, illuminating trends that vary across cities depending on their size, public transit options, and drivability. 

Some key findings include:

• A majority of travelers would have used a car or taxi or walked had ridesharing not been available. In some large cities, ridesharing replaces a significant portion of public transit trips.
• Nationally, ridesharing has led to modest increases in total vehicle miles traveled and greenhouse gas emissions—0.08 percent and 0.14 percent, respectively. 
• The effects of ridesharing differ across cities, partly because of differences in each city's drivability and public transit options. For example, San Francisco sees an increase in vehicle miles traveled of 1.38 percent. 
• If policymakers regulate ridesharing to reduce traffic congestion, it may be beneficial to do so at a local level to account for the different impacts from city to city.