"And there aren't many methods for assessing such complex social problems," Dubljevi? says. "One approach is to break the large problem down into a collection of more specific questions, assessing different risks and potential benefits separately. This approach is called multi-criteria decision analysis, and it's what we did here."
For this study, the researchers outlined four different scenarios for the future of AVs:
- No AVs allowed on public roads;
- AVs are allowed, with no regulations;
- AVs are allowed, but are regulated;
- AVs are regulated and can only be owned by commercial fleet operators.
The researchers then convened a panel of 19 experts with expertise in subjects such as computer science, political science, transportation and ethics.
The researchers also created a list of 13 potential harms and eight potential benefits associated with deploying AVs. The list was developed based on documents from the National Academies and other federal agencies, as well as input from the expert panel convened for the study. Potential harms included assessments of increased risk of accident deaths or cases of injury. Potential benefits included assessments of economic benefits and curtailing environmental impact by reducing traffic jams.
The expert panel then reviewed the four AV deployment scenarios with the goal of determining which scenarios had the best ratio of benefits to harms.
"To assess the potential impact of AV deployment, you have to compare it to a baseline," says George List, co-author of the study and a professor of civil engineering at NC State. "The baseline was our current state of affairs. And our current state of affairs is that there are a tremendous number of deaths and injuries on U.S. roads.
"While AVs are not perfect, all of our predictions suggest that they will be a step in the right direction. Prohibiting the use of AVs on U.S. roads was the least promising scenario."
However, the expert panel also highlighted the extent to which government regulations could help reduce risk.
"For example, regulations could limit use of AVs in urban environments and areas with high pedestrian traffic," Dubljevi? says. "Either of the regulated scenarios is better than allowing unregulated AVs on the road."
So, which scenario offered the most benefits and the fewest risks?
"Regulating AV use and limiting ownership to commercial fleet operators is a little more promising than allowing the general public to own and operate their own AVs," Dubljevi? says. That's because fleet ownership makes it more likely that AVs will be properly maintained, software updates will be made on time, and so on.
"We hope that federal, state and local governments use our findings to review whatever regulations they have in place concerning the use of autonomous vehicles -- or to develop regulations if there are none on the books," Dubljevi? says.
The work was done with support from the Kenan Institute of Science and Technology and North Carolina State University Research and Innovation.