The environmental trade-offs of autonomous vehicles
Optimistic predictions expect reliable autonomous vehicles to be commercially available by 2030, at a time when mobility is undergoing a profound shift far away from traditional modes of transportation and towards door-to-door services. Previous analysis suggested that conveyance will lose market share to autonomous vehicles, but the environmental impact of adjusting transport use has hardly been considered. New research shows that the convenience of autonomous vehicles would likely come at an environmental cost.
A recent paper by researchers from the University of Wisconsin-Madison addresses the use-phase implications of autonomous vehicles employing a stated preference survey to reveal the potential users of autonomous vehicles and the resulting level of competition with traditional modes of transport. The results show an expected increase in environmental impacts across all the categories studied, thanks to a shift from less carbon-intensive transportation options. The authors also confirm that the utilization of electrical autonomous vehicles could change this environmental outcome. Their research is published today in the journal Environmental Research Letters.
Autonomous vehicles are expected to supply significant benefits in terms of transport operations, safety, and accessibility; however, these benefits may mask potential environmental impacts. Clearly, the adoption of autonomous vehicles is going to be amid travel behavior changes, however, research so far has mostly focused on autonomous vehicle technology and not on the environmental impacts which will result from transport mode shifts. This new research, therefore, examines these impacts supported four categories: energy consumption, greenhouse emission emissions, particulates, and pollutants.
A survey conducted in Madison, Wisconsin, examined attitudes to move modes and located that in choice experiments between private vehicles, autonomous taxis, buses, and bicycles, respondents would use autonomous vehicle taxis 31% of the time thanks to their desirable operational and modal attributes. By contrast, buses had a significantly longer time interval thanks to walking and waiting, and private vehicles were the midway choice. However, commuters who owned a private vehicle were less likely to settle on an autonomous vehicle, implying that autonomous vehicles primarily compete with public transport; therefore, policies getting to reduce commuting in personal vehicles won’t be fully successful in reducing environmental impacts.
The researchers then examined the impacts of policy and repair changes via a series of simulations, which confirmed that autonomous vehicles primarily compete with the environmentally preferred transport mode, buses. They also showed that a decrease in bus travel times would end in a big increase in bus usage. The environmental predictions showed increases of between 5.7% and 6.85% within the energy and pollution categories, a big impact, as long as transport accounts for 28% of the greenhouse emission emissions in the U.S.
To offset the environmental impacts of autonomous vehicles, the researchers considered the utilization of electrical autonomous vehicles, considering the utilization phase only. The results showed that electric autonomous vehicles can offset the environmental impact of autonomous vehicles, subject to an appropriate mixture of electricity generation methods, and if the adoption rate of electric autonomous vehicles is over about 40%.
This new research into the use-phase environmental impacts of these vehicles will help researchers and policymakers to take advantage of the complete potential of autonomous vehicles while taking any potential environmental implications into account. Cities seeking to deploy this vehicle will be got to steer their deployment in ways in which both match consumer adoption patterns and are environmentally beneficial.
Author Wissam Kontar said: “The transportation is on the verge of a serious paradigm shift. Emerging technologies as autonomous and electric vehicles, alongside a change in commuting behavior, will have significant operational and environmental impacts. It is of crucial importance that we consider those impacts conjointly if we are to forge efficient and sustainable mobility in the longer term.