UCLA

The rapid growth of ridesourcing services, provided by Transportation Network Companies (TNCs) like Uber and Lyft, has uncertain environmental impacts. Although the ridesourcing services can potentially reduce the environmental costs of single occupancy driving (SOV) over the “life cycle” of auto ownership and use, including emissions from driving, auto manufacturing, end-of-life disposal, and infrastructure (roads and parking), it can also increase travel by reducing its cost. This research analyzes and compares different SOV and TNC travel scenarios using a conceptual model applied to travel behavior data from the city of San Francisco. The results show that: (1) There exists a “green point” ranging from 5 to 40 percent, which is the level of induced trips that makes TNC emissions exceed SOV emissions; (2) Hybrid and electric vehicles contribute to emissions reduction across all scenarios. Higher fuel economy and cleaner energy can not only help reduce greenhouse gas emissions when there are no induced trips, but also slow GHG emission growth as the level of induced trips goes up; (3) Hybrid vehicles appear a more cost-effective alternative to electric vehicles for reducing pollution; (4) Vehicle cost and the spread between gasoline and electricity price are critical factors influencing the cost-effectiveness of electric vehicles; (5) States with a clean electric grid and high spread between gasoline and electricity prices (e.g. California, Washington) are the best candidates for electrification of private vehicles and TNC fleets.