Deep Decarbonization from Electrified Autonomous Taxi Fleets: Life Cycle Assessment and Case Study in Austin, TX

CSS Publication Number: 
CSS19-27
Abstract: 

Although recent studies of autonomous taxis (ATs) have begun to explore potential environmental implications of fleet deployment, little is known about their impacts over the long term. We present a holistic life-cycle assessment framework that incorporates both direct and indirect effects of ATs at the subsystem, vehicle, and mobility-system levels. Eco-driving and intersection connectivity are the direct effects analyzed along with indirect effects that include empty kilometers, parking, charging infrastructure, powertrain rightsizing, electric vehicle adoption, ride-sharing, and fleet-turnover rates. A case study of an AT fleet in Austin, Texas from 2020 to 2050 with constant travel demand indicates the strategic deployment of an electrified AT fleet can reduce cumulative energy and greenhouse gas (GHG) emissions by 60% in the base case, with a majority of this benefit resulting from electrified powertrains. Further reductions up to 87% can be achieved with accelerated electrical grid decarbonization, dynamic ride-share, longer vehicle lifetime, more energy efficient computers, and higher new-vehicle fuel-consumption rate reductions. We highlight the major opportunities for maximizing the environmental performance of AT fleets over the long term.

Research Areas: 
Keyword: 
Life cycle assessment
GHG emissions
autonomous taxi
shared autonomous vehicle
connected and automated vehicle (CAV)
fleet turnover
Publication Type: 
Journal Article
Transportation Research Part D: Transport and Environment
Date Published: 
Accepted June 17, 2019
Persistent URL: 
https://doi.org/10.1016/j.trd.2019.06.007
Full Citation: 
Gawron, James, Gregory Keoleian, Robert De Kleine, Timothy Wallington, Hyung Chul Kim. (2019) “Deep Decarbonization from Electrified Autonomous Taxi Fleets: Life Cycle Assessment and Case Study in Austin, TX.“ Transportation Research Part D: Transport and Environment 73: 130-141.
Admin Content
Publication Status: 
Published