Energy and environmental impacts of shared autonomous vehicles under different pricing strategies

There are still many uncertainties about the environmental and energy effects of SAVs, and some researchers and policymakers have concerns about whether SAVs are beneficial for sustainable social development^17,18. On the one hand, SAVs can save energy and reduce emissions by, for example, promoting transportation efficiency¹⁸, increasing road capacity¹⁹, mitigating congestion¹⁹, reducing accident frequency²⁰, matching vehicle sizes to trip requirements¹², and eco-driving²¹. On the other hand, SAVs can lower people’s marginal travel costs and make the locational decisions of residents and enterprises more free, leading to urban sprawl and increased travel time, distance, and frequency^22,23. SAVs are also likely to increase travel by specific user groups (e.g., elderly, children, the disabled) who cannot drive by themselves in daily life, thus increasing travel demand, resulting in more vehicle kilometers traveled^10,24 and significant increases in energy consumption and emissions, which will affect sustainable development. In short, SAVs seem to be a double-edged sword. This raises the question of whether, in the long-term, promoting SAVs will reduce or increase transportation-related GHG emissions and energy consumption.