National Center for Sustainable Transportation

This study evaluates the energy consumption and emission characteristics associated with rideshare and transit electrification in the Houston metropolitan region using the U.S. Department of Energy’s Systems and Modeling for Accelerated Research in Transportation (SMART) Mobility workflow. An integrated modeling framework combining POLARIS, stochastic vehicle trip prediction (SVTrip), and Autonomie was used to examine travel demand, vehicle operations, energy consumption, and emissions under multiple passenger vehicle electrification scenarios. Scenarios included a baseline condition, electrification of a 20,000-vehicle Transportation Network Company (TNC) fleet, full passenger vehicle fleet electrification, expansion of the electrified TNC fleet to 40,000 vehicles, and a separate transit bus electrification assessment. Results indicate that battery electric vehicles generally exhibited lower energy consumption and modeled greenhouse gas emission rates than conventional internal combustion engine vehicles, with average energy consumption of approximately 0.214 kilowatt-hours per kilometer. The transit bus assessment, based on simulated service mileage and published emission factors, estimated approximately 67% lower operational greenhouse gas emissions for battery electric buses compared with conventional diesel buses under equivalent service mileage assumptions. The findings provide insights into vehicle-level energy consumption and emission characteristics under alternative electrification assumptions and illustrate the potential operational emissions advantages of electric transit buses.

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