Users’ Trust in and Concerns about Automated Driving Systems

This brief examines people’s trust and potential adoption of automated vehicles (AVs). It also assesses how people’s concerns about different levels of AVs differ in relation to their degree of trust in AVs to prevent crashes.

April 2021

Suggested Citation


  • Woon Kim

  • Tara Kelley-Baker


In the past several years, numerous studies have examined public attitudes, beliefs, and acceptance of automated vehicles (AVs) with mixed results. Some studies found participants had positive sentiments about AVs, while other studies found participants had neutral or even negative opinions about such vehicles. In several studies, even those participants who agreed that AVs would offer potential benefits and had overall positive attitudes towards them expressed concern about AV-related issues, such as system equipment failure and vehicle performance in unexpected situations.

As a follow up to a 2019 AAA Foundation for Traffic Safety study examining public understanding, expectations about AVs, and the rationales behind their distrust and discomfort towards vehicle automation, this brief aims to examine people’s trust in, adoption of, and concerns about different levels of AVs.

Key Findings

The results show people were more likely to trust lower-level AVs (Levels 2 and 3) than higher-level AVs to reduce crashes. Additionally, more people preferred to own vehicles with lower levels of automation. Compared with those trusting AVs to prevent crashes, people who distrusted AVs were significantly more concerned about all potential AV-related issues, such as technology malfunctioning, drivers’ over-reliance on automation, technology distraction/annoyance, vehicle hacking, and data privacy. These results highlight the importance of public education and training on AVs’ capabilities and limitations in order to increase public trust and reduce concern.


The data used for this study came from the Traffic Safety Culture Index, a national survey conducted annually by AAA Foundation for Traffic Safety. In 2018, a set of questions inquiring about public understanding, expectations, and concerns across different levels of AVs was added.

For these data, an online research panel was used to survey U.S. residents ages 16 or older in English and Spanish in the fall of 2019. The panelists were recruited based on standard probability-based random digit dial and address-based sampling methods to be representative of the U.S. household population. A total of 3,511 respondents completed the survey.

This study conducted descriptive analyses with a Pearson’s Chi-squared test on weighted data and reported results on the following topics:

  • Prevalence of public trust and adoption of automated vehicles in 2019 compared with 2018.
  • Prevalence of public concern about automated vehicles in 2019 compared with 2018.
  • People’s concerns about automated vehicles in relation to their degree of AV trust.

Trust was measured with the survey item “How much would you trust each level of technology to reduce the likelihood of a crash happening?” Further, adoption was measured by respondents’ preferred level of AV to own in the next couple of years, if cost was no barrier.


In general, people were more likely to trust lower-level AVs (Levels 2 and 3) than higher-level AVs for crash prevention. The results showed no considerable changes between 2018 and 2019.

With respect to adoption, more respondents indicated that they would be ‘most comfortable’ owning vehicles with lower levels of automation than with higher levels. In 2019, compared with 2018, there was a substantial increase in respondents’ reporting they felt most comfortable owning vehicles with either no automation or just Level 1.

Public concern about AV technology malfunctioning increased as the AV level increased. Additionally, people indicated that purchase price was also a major concern for Level 4 and 5 AVs. For Level 3 vehicles, people’s top concern was drivers’ over-relying on automation technology. Comparing results from 2018 with 2019, people showed increased concern about drivers’ over-reliance on Level 3 technology, whereas concern about vehicle hacking in Level 4 decreased considerably in 2019.

People who reported distrusting AVs were significantly more concerned about all issues compared with those who reported trusting AVs, regardless of automation levels. Over 80% of participants who distrusted Levels 2, 3, and 4 considered technology malfunctioning the greatest concern. The top three concerns regarding Level 5 automation were no control of driving, technology malfunctioning, and no manual driving option.

In contrast, the top concern for those who trusted AVs was the purchase price across all AV levels, including Levels 3, 4, and 5 when these vehicles become available on the market. The second top concern among those who trusted AVs was the technology malfunctioning across all AV levels.

Suggested Citation


Woon Kim

Tara Kelley-Baker