A new report published by the National Highway Traffic Safety Administration (NHTSA) provides insights into how drivers respond to vehicles identified as “self-driving,” helping transportation researchers and policymakers better understand interactions that can inform the safe integration of automated driving technologies on public roads. Westat conducted the research. The report was authored by James W. Jenness, PhD; Amy K. Benedick; Jeremiah P. Singer; and Richard Huey.
In the report, “Conventional Vehicle Driver and Automated Driving System-Equipped Vehicle Interactions,” Westat researchers examined how drivers behaved around a research vehicle that alternated between the appearance of a conventional vehicle and a mock automated driving system (ADS)–equipped vehicle during trips on a fixed public freeway route.
Observers found that drivers were noticeably more attentive to the mock ADS vehicle. Compared with the conventional vehicle, nearby drivers looked at it more frequently and for longer periods, displayed surprised expressions, made gestures, or even used their phones to take pictures or videos as they approached or passed it. Drivers also generally took longer to pass the mock ADS vehicle.
Despite the increased attention, the study found no statistically significant differences in objective measures of potentially unsafe driving behaviors, such as cutting in front of the research vehicle or following too closely. It is important to note, however, that due to the study’s naturalistic design, it did not capture other indicators of distraction, such as how much time drivers spent with their eyes off the forward roadway.
“The findings contribute to a growing body of research on how the public interacts with emerging automated driving technologies and provide evidence that, while self-driving vehicles may attract greater curiosity from surrounding drivers, they do not necessarily lead to more unsafe driving behaviors under the conditions studied,” noted Benedick.