As ride-sharing grew rapidly, US road congestion increased by almost 1 percent while the duration of congestion rose by 4.5 percent, according to a study conducted by Future Urban Mobility (FM) Interdisciplinary Research Group (IRG) at Singapore-MIT Alliance for Research and Technology (SMART), MIT, and Tongji University.
TNCs, also known as ride-sharing firms, have exploded in popularity around the world, with more and more cities joining the trend. Is ride-sharing really more environmentally friendly than taxis and private cars, or do they instead add to traffic congestion?
The first-of-its-kind research analyzed three dimensions of how ride-sharing (more accurately called ride-hailing) affects urban mobility in the United States — road congestion, public transit ridership, and private car ownership — and how they have grown over time in a paper titled “Impacts of transportation network companies on urban mobility” recently published in Nature Sustainability.
“While public transportation provides high-efficiency shared services, it can only accommodate a small portion of commuters, as their coverage is limited in most places,” says Jinhua Zhao, SMART FM principal investigator and associate professor at MIT Department of Urban Studies and Planning. “While mathematical models in prior studies showed that the potential benefit of on-demand shared mobility could be tremendous, our study suggests that translating this potential into actual gains is much more complicated in the real world.”
The researchers found that the entrance of TNCs resulted in increased road congestion in terms of both severity and length, using a panel dataset covering mobility patterns, socio-demographic shifts, and TNC entry at the metropolitan statistical areas level to create a collection of fixed-effect panel models.
Congestion increased by nearly 1%, while congestion period increased by 4.5 percent, according to the research. They also discovered an 8.9% decline in public transportation use and a 1% drop in private car ownership.
Although several previous studies have concentrated solely on Uber, this one considers both Uber and Lyft, the two most common ride-sharing companies in the US. Although Uber owns 69 percent of the market, Lyft owns a significant 29 percent, and including it in the dataset will provide a more comprehensive and impartial picture of the TNC impact.
The study also discovered that having convenient access to ride-sharing deters riders from using greener options like biking or public transportation. According to survey data from different U.S. cities, about half of TNC trips would have been made otherwise by walking, cycling, public transportation, or not at all.
“We are still in the early stages of TNCs and we are likely to see many changes in how these ride-sharing businesses operate,” says Hui Kong, SMART-FM alumna and postdoc at the MIT Urban Mobility Lab, and an author of the paper. “Our research shows that over time TNCs have intensified urban transport challenges and road congestion in the United States, mainly through the extended duration and slightly through the increased intensity. With this information, policies can then be introduced that could lead to positive changes.”
The researchers believe that TNCs’ large number of deadheading miles (miles driven without a passenger) may lead to their negative impact on traffic congestion. Deadheading miles account for about 40.8 percent of TNC miles, according to other reports.
“Our findings can provide useful insights into the role that TNCs have played in urban transport systems,” says Professor Mi Diao of Tongji University and SMART-FM alumnus, the lead author of the paper. “It can be very useful in supporting transportation planners and policymakers in their decisions and regulations with regard to TNCs.”
SMART is conducting the study, which is funded by the National Research Foundation (NRF) Singapore’s Campus for Research Excellence and Technological Enterprise (CREATE) program.
In SMART, FM is one of five IRGs. FM uses new technical and structural technologies to build the next generation of urban mobility networks, enhancing connectivity, equity, protection, and environmental efficiency for Singaporeans and businesses around the world.
MIT’s research enterprise in Singapore, SMART, was established in 2007 in collaboration with the NRF. The first entity in the CREATE is SMART. SMART acts as an intellectual and innovation centre for MIT-Singapore research collaborations, pursuing cutting-edge research ventures in areas of mutual interest.
Antimicrobial Resistance, Critical Analytics for Manufacturing Personalized-Medicine, Disruptive and Sustainable Technologies for Agricultural Precision, FM, and Low Energy Electronic Systems are among the five IRGs that make up SMART at the moment.