Abstract:Three revolutions are underway in urban transportation around the world: vehicle electrification, automation, and shared (on-demand) mobility. The manner in which each of these unfolds, and how they interact, will have major implications for urban transportation energy use and CO₂ emissions over the coming decades. Our modeling work suggests a wide range of possible impacts and a strong need to pursue policies that move these revolutions in societally optimal directions, notably toward large-scale sharing (pooling) of rides. This Commentary summarizes and extends this work.