The effects of automation failure and secondary task on drivers’ ability to mitigate hazards in highly or semi-automated vehicles

In Advances in Transportation Studies an international Journal 2016 Special Issue, Vol. 1

In this article co-authored by Avinoam Borowsky and myself in memory of our missed colleague Dr. Adi Ronen who initiated this research, we present an experimental test-bed for evaluation of levels of vehicle automation, in-vehicle secondary tasks, and hazardous scenarios.

  • Four levels of automation were implemented – Manual-no automation (M), Adaptive Cruise Control (ACC), Automatic Steering (AS), and Automated Driving (AD).
  • Two types of secondary tasks were included: (1) Driving related. This task required on road glances; (2) Driving unrelated.

The BGU driving simulator (Left) and the in-vehicle secondary task “squares task” (Right)

In the “squares task”, drivers observe nine squares on the in-vehicle display  to identify the lighted square. Once identified, the driver is required to press on the lighted square, then another square is lighted and so on. Once the secondary task begins, drivers have 5 seconds to accurately press on as many squares they can until the task ends. They receive a printed feedback after each press either showing the response time or indicating that the press was erroneous.

An empirical evaluation was conducted to examine how well drivers mitigate road hazards when automation fails unexpectedly, looking at situations where drivers were either engaged with secondary tasks or not prior to the automation failure and/or the hazardous event.  In each driving section, typical hazardous events appeared. Automation failure (i.e., the need to assume manual control) was alerted by sound and visually on the touchscreen.

Results showed that while engagement with a non-driving related secondary task lead to more crashes, automation failure did not, especially when drivers were monitoring the road. In addition, drivers’ performance on the secondary task revealed differential effects of automation mode with respect to the road conditions.


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