Cognition, Technology & Work

, Volume 21, Issue 1, pp 41–54 | Cite as

The effect of reliability on drivers’ trust and behavior in conditional automation

  • Chris SchwarzEmail author
  • John Gaspar
  • Timothy Brown
Original Article


The development of automated vehicles continues unabated. The human factor challenges of designing safe automated driving systems are critical as the first several generations of automated vehicles are expected to be semi-autonomous, requiring frequent transfers of control between the driver and vehicle. Conditional automation raises particular concerns about drivers being out of the loop. A driving simulator study was performed with 20 participants to study driving with conditional automation. We observed driver performance and measured comfort as an indicator of the development of trust in the system. One scenario used a more capable automation system that was able to respond to most events by slowing or changing lanes on its own. The other scenario used a less capable automation system that issued takeover requests for all events. Participants drove both scenarios in counterbalanced order and experienced the different capabilities as changes in reliability. The automation would behave one way in the first work zone and a different way in the second. We observed three types of comfort profiles over the course of the drives. Several behavioral measures, notably gaze, showed effects of reliability variations. Trust calibrated during the first-driven scenario was seen to affect behavior during the second one, and this effect was more pronounced in the older age group, and most pronounced for women in that group.


Trust in automation Conditional automation Automated vehicles Reliability 



This research was funded by the Safer-Sim University Transportation Center.


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Copyright information

© Springer-Verlag London Ltd., part of Springer Nature 2018

Authors and Affiliations

  1. 1.National Advanced Driving SimulatorThe University of IowaIowa CityUSA

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