Citation

DeGuzman CA, Hopkins SA, Donmez B. Transp. Res. Rec. 2020; 2674(4): 140-151.

Copyright

(Copyright © 2020, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

10.1177/0361198120912228

PMID

unavailable

Abstract

Today's vehicles are becoming highly automated, however, if the automation fails, drivers must take over control of the vehicle. Automation may fail as a result of known system limits (system-limit failure) or of malfunctions that are unforeseen by system designers (system-malfunction failure). The aim of this research was to quantify the differences between how these two failure types influence driver takeover performance and monitoring behaviors. In a simulator with SAE Level 2 driving automation, 18 drivers experienced both a system-limit and system-malfunction failure while engaging in a secondary task.

RESULTS show that drivers put their hands on the wheel 0.62 s sooner and took over 0.51 s faster for the system-limit failure compared with the system-malfunction failure. Eye tracking data revealed that the percent of time looking at the secondary task display was 12.7% lower and the percent of time looking at the roadway was 11.2% higher before the system-limit failure compared with before the system-malfunction failure. Given that takeover performance and monitoring behavior differ significantly based on failure type, a distinction should be made in the literature between system-limit and system-malfunction failures, and comparisons between previous studies using these failures should not be done without considering this distinction. Furthermore, as SAE Level 2 vehicles are currently available to consumers, efforts should be focused on supporting drivers' mental models of automated systems, so that drivers are able to successfully predict system-limit failures.

Language: en