Transportation now generates more carbon dioxide emissions than any other United States economic sector, and, at the same time, new mobility options are rapidly changing transportation. On-demand ride-hailing companies like Uber and Lyft now provide mobility services that both complement and compete with public transit, personal vehicle and non-motorized options. Within a relatively short period of time, these Transportation Network Companies (TNCs) have expanded across the United States and have introduced new options to riders, such as shared ride services. A growing body of literature indicates that ride-sharing can provide numerous transportation, infrastructure, environmental, and societal benefits. However, regardless of these benefits, the U.S. population has not embraced ride-sharing. Motivated by the important role ride-sharing may play in reducing costs, vehicle miles traveled, road congestion, emissions and the limited use of ride-sharing services in the U.S., this study seeks to provide a deeper understanding of the social and behavioral considerations associated with travelers’ acceptance of shared rides and how those considerations factor into individuals' willingness to pay for shared services. The team conducted research using a variety of methods, including a literature review, a web-based consumer survey, and focus group discussions. This combination of methods provides an in-depth understanding of whether and under what conditions people are willing to accept and pay for shared-rides. Results can be used to 1) inform policymakers and TNC executives on what influences the likelihood of an individual to choose a shared-ride over a solo-ride; 2) help TNC decision-makers competitively price their shared services to increase adoption and decrease transit pollution per capita; and, 3) provide insight into complementary services, such as conversation options, that may increase the adoption rates.