Towards the close of the first decade of the 21st Century, ride-hailing services began to enter the transportation market through smart phone applications that allowed consumers to hail and pay for a ride from drivers using their own vehicle. The information and communication technologies used by these platforms allow for more reliable service, to more locations, with shorter wait times, and at a lower cost than traditional taxi services and, perhaps, public transit. Today, an estimated 15% of adults across the U.S. and 21% in major cities have personally used these services. The successful entrance of ride-hailing services into the transportation market has raised questions about their effect on the overall transportation system, including congestion, total vehicle miles traveled (VMT), and greenhouse gas emissions (GHGs). Reliable answers are limited, in large part, because of their rapid expansion and the lack of publicly available data from these private ride-sharing companies. However, there is now a small body of research, most conducted in 2016 and 2017, that provides some initial evidence on the impacts of these services. This research includes population representative survey data, targeted ride-hailing user survey data, and measured ride-hailing driver and passenger activity data. In addition, the recent interest in automated vehicles has produced modeling studies that also provide insight into the potential effects of ride-hailing services. The following framework was developed to identify the range of possible travel effects, both positive and negative, on users of ride-hailing services. This includes the effects of ride-hailing on auto ownership, trip generation, destination choice, mode choice, network vehicle travel, and land use.