Researchers at MIT report that the entrance of transportation network companies (TNCs)—specifically Uber and Lyft, which together have a 98% share of the market—in cities led to increased road congestion in terms of both intensity (by 0.9%) and duration (by 4.5%); an 8.9% decline in transit ridership; and an insignificant change in vehicle ownership.

In their open-access paper published in Nature Sustainability, the MIT team concludes that despite the ideal of providing a sustainable mobility solution by promoting large-scale car sharing, TNCs have intensified urban transport challenges since their debut in the United States.

Built on the concept of the sharing economy, transportation network companies (TNCs) have emerged as a new mode of transport that has significantly affected urban mobility in the past decade, even though TNC trips remain a small fraction of the overall miles travelled. TNCs use online platforms to provide rides on demand by connecting passengers with drivers using their private vehicles based on real-time information. TNCs enable both the sharing of vehicles where one passenger or one group of passengers enjoys and pays for the ride exclusively (for example, UberX and Lyft) and the sharing of trips by unacquainted passengers with similar origins and destinations who split the fare (for example, UberPool and Lyft Shared).

Many researchers have estimated the benefit of on-demand mobility sharing using mathematical models, finding great potential. … Despite the substantial theoretical benefits of on-demand shared mobility, the actual role of TNCs in urban transport systems is under intense debate and their impact on the sustainability of cities remains unclear.

… In this study, we aim to systematically examine how TNCs have changed urban mobility in the United States as measured by road congestion, PT ridership and private vehicle ownership, using a panel dataset covering mobility trends, sociodemographic changes and TNC entry in all the metropolitan statistical areas (MSAs) that had Uber and/or Lyft as of 2016 and report their PT ridership regularly.

—Diao et al.

Unlike previous studies that focused only on Uber, the dataset developed by the MIT team allowed them to take both Uber and Lyft into account.

The researchers noted that generally, the TNC effects on the duration of congestion, public transit ridership and vehicle ownership increase over time, while PT ridership seems to stabilize after three years of entry. The entry of the second TNC operator can further reduce PT ridership and extend the duration of congestion, possibly due to the lower prices and better services resulting from the competition between TNC operators.

They said that this result is also consistent with the finding that TNCs affect congestion duration more than intensity.

Commenting on the study, Uber noted that its fastest growth coincided with the rapid economic expansion following the Great Recession. That, along with other concurrently changing socioeconomic factors, make it difficult to tie a specific outcome to a cause such as Uber’s entry in cities, an Uber spokesperson suggested.

Uber also noted that the 7.7% drop in transit ridership in the year of TNC entry would have occurred when the number of trips would generally be quite low.

While we are skeptical about the methodology of this study (and other studies have found conflicting results), we will continue to work hard to create a greener and better future for all, while helping the transition away from using personal cars.

—Uber spokesperson

Uber said it is investing some $800 million in resources to help drivers switch to electric, to measure and publicly report on emissions from customers’ use of Uber products, and to launch features to encourage transit use around the world.

Resources

• Diao, M., Kong, H. & Zhao, J. (2021) “Impacts of transportation network companies on urban mobility.” Nat Sustain doi: 10.1038/s41893-020-00678-z