The Effects of Ride-Hailing Services on Greenhouse Gas Emissions

Ride-hailing services, which allow consumers to order and pay for rides through smart phone applications, have grown to a substantial proportion of the transportation market. Today, an estimated 15% of adults across the U.S. and 21% living in major U.S. cities have used ride-hailing services. The growth of ride-hailing services has raised questions about their overall effects on the transportation system. While they clearly offer a new form of mobility, there is concern they may increase congestion and air pollutant emissions. A limited number of studies have attempted to quanitfy changes associated with the increased use of ride hailing services. UC Davis researchers examined how ride-hailing affects the total amount of driving (measured in vehicle miles traveled, VMT) as well as greenhouse gas (GHG) emissions. The researchers developed a framework of categories for analyzing the multiple aspects of transportation that may be affected by ride-hailing. These categories are: automobile ownership; number of vehicle trips generated; choice of mode of travel; empty (passenger-less) travel between drop-off and pick-up points, known as “network travel”; and destination choice and land use. Thirteen (13) studies were analyzed using this new framework: 8 used surveys of riders or recorded data on rider and driver activity; and 5 used simulated (“modeled”) travel in and around cities by automated taxis. By compiling multiple studies in the framework, stronger and more certain conclusions could be reached. View the NCST Project Webpage