Will the Automated Vehicle Revolution be Green?

Last week’s release of the Intergovernmental Panel on Climate Change (IPCC) special report highlights the “rapid and far-reaching” societal transformations required in order to limit warming to 1.5, or even 2 degrees Celsius. A new study by researchers at the University of Michigan, published in the journal Environmental Science & Technology, highlights the role of connected and automated vehicles (CAVs) in ushering in a low-emissions future. This research sheds new light on a largely understudied aspect of the coming CAV revolution. In my first post for the Journal of Law and Mobility, I will summarize that study and provide key takeaways for policymakers.

The Michigan study identifies several factors that will cause CAVs to emit more greenhouse gases than comparable human-driven vehicles. The weight of sensors and the computer system necessary to operate an CAV, the power consumed by the computer system, in particular the mapping function used to create high definition charts of the car’s surroundings, and the increased drag from cameras and sensors mounted on the outside of the vehicle, all operate to increase emissions. Depending on the weight of the equipment and power usage of the computer, these factors were found to increase emissions by between 2.8% and 20% relative to a comparable human driven car.

These factors are expected to be partially, if not entirely, offset by the car’s ability to create more favorable traffic patterns and identify more efficient routes. This extra efficiency is expected to more than offset any increase in weight, power usage, and drag under some scenarios, and turn a relatively large emissions increase into a more modest one under others. All things considered, the study finds that the emissions impact of CAVs will range from a 9% reduction to a 5% increase.

Many of the obstacles to reducing CAV emissions are engineering challenges: reducing the weight and power consumption of computer systems, and improving the aerodynamics of external sensors. Policymakers role in solving these challenges are likely to primarily take the form of support for university research and/or tax credits for private sector research on improving the efficiency of CAVs.

Policymakers do however have a significant role to play in improving the network effects of automated vehicles, such as reduced congestion. After the proper levels of safety, security, and reliability are obtained, a high volume of CAVs on the road increases the efficiencies that can be gained through cars communicating with each other to ease the flow of traffic. Laws that ensure high standards for data privacy and CAV safety can give consumers the confidence needed to use CAVs at a higher rate. Regulatory schemes that ease the entrance of CAV fleets into a city’s vehicular landscape can promote early adoption.

Particularly as the technology advances, CAVs have a role to play in reducing harmful greenhouse gas emissions. Widespread adoption of the technology can maximize these benefits, paving the way for large fleets of CAVs that create strong network efficiencies. As the technology advances to a point of being safe for public use, policymakers should account for these potential benefits as they consider the advent of CAVs in their cities.