This project will investigate the travel behavior and choices of TNC drivers and riders using recently-collected travel diary data in the Sacramento Area Council of Governments (SACOG) region. As part of this research, we plan to look at the travel pattern of Uber/Lyft drivers to better understand how TNCs contribute to traffic congestion during peak hours and non-peak time, and what their contributions to total VMT are, due to deadheading and other "off the clock time" drivers' VMT. To expand this analysis, we plan to conduct a follow-up survey to be distributed to the same drivers, which will help us better understand the differences in travel behavior of various groups of drivers and how sociodemographics, individual attitudes and preferences, as well as the characteristics of the built environment affect these variations. In addition, we plan to investigate under what circumstance individuals are more likely to use ridehailing services, e.g. estimating a mode choice model for the SACOG area. This will help us to better understand the impact of ridehailing on mode split and will help quantify the potential impacts of ridehailing on vehicle ownership over time.