This research investigates how an emerging service - transportation network companies (TNCs) - impacts mobility and energy use. Several TNC areas were identified as key factors impacting transportation and energy
including vehicle type, mode shifts, pooling, and deadheading. Using detailed data on individual rides provided by a TNC in Austin Texas, this study quantify the additional vehicle miles traveled (VMT) TNC drivers traveled without passengers (i.e., deadheading) to be 45%, and nearly equaled VMT with passengers. While deadheading increases energy use, vehicles used for ride-hailing tend to be newer, and more fuel efficient (twice as many hybrid-electric vehicles and on average, 3.2 miles per gallon more fuel efficient) than comparable vehicles registered in Austin. Considering deadheading, fuel efficiency, and estimates of passenger pooling and modal shift (from literature), this study suggest that TNCs may increase energy use by 41-90% net compared to baseline pre-TNC personal travel. Preliminary effects of TNC services on vehicle registrations across urban areas may indicate an increase in vehicle registrations of about 1%. However, the effect of TNC entry varies by type of city, ranging from a 3.5% increase to a 0.7% decrease in vehicle registrations. This suggests that ride-hailing may induce demand for vehicle ownership, at least in the short to medium run.