Ipsilateral and contralateral warnings: effects on decision-making and eye movements in near-collision scenarios

Abstract

Cars are increasingly capable of providing drivers with warnings and advice. However, whether drivers should be provided with ipsilateral warnings (signaling the direction to steer towards) or contralateral warnings (signaling the direction to avoid) is inconclusive. Furthermore, how auditory warnings and visual information from the driving environment together contribute to drivers’ responses is relatively unexplored. In this study, 34 participants were presented with animated video clips of traffic situations on a three-lane road, while their eye movements were recorded with an eye-tracker. The videos ended with a near collision in front after 1, 3, or 6 s, while either the left or the right lane was safe to swerve into. Participants were instructed to make safe lane-change decisions by pressing the left or right arrow key. Upon the start of each video, participants heard a warning: Go Left/Right (ipsilateral), Danger Left/Right (contralateral), and nondirectional beeps (Baseline), emitted from the spatially corresponding left and right speakers. The results showed no significant differences in response times and accuracy between ipsilateral and contralateral warnings, although participants rated ipsilateral warnings as more satisfactory. Ipsilateral and contralateral warnings both improved response times in situations in which the left/right hazard was not yet manifest or was poorly visible. Participants fixated on salient and relevant vehicles as quickly as 220 ms after the trial started, with no significant differences between the audio types. In conclusion, directional warnings can aid in making a correct left/right evasive decision while not affecting the visual attention distribution.

Comparison of Experienced and Novice Drivers’ Visual and Driving Behaviors during Warned or Unwarned Near–Forward Collisions

“…When considering gaze behaviors, the FCWS did reduce the spread of search in the Y-axis dimension and the number of fixations compared to the NA condition. Gaze data are consistent with earlier observations [23][24][25][26] and could be interpreted as a visual-attentional focus on the relevant elements of the driving situation. Still, these visual strategies changed, and the associated improved visual perception of the situation did not transfer to more efficient driving behaviors.…”

“…In the absence of the FCW, drivers were also observed to come closer to a collision with the lead vehicle [22]. Such warning benefits could be related to gaze redirection toward relevant elements of the driving scene [23][24][25][26].…”

Now or never: Eye tracking and response times reveal the dynamics of highway merging decisions

“…This task is safety-critical, resulting in approximately 19.000 accidents per year in the US alone (Sen et al, 2003). Better understanding of human merging behavior can aid in designing improved traffic infrastructure (Zheng and McDonald, 2007), development of advanced driver assistance systems (Baumann et al, 2011;Gonçalves et al, 2022;de Winter et al, 2022;Duan et al, 2023) and automated vehicles capable of interacting with human traffic participants (Sadigh et al, 2018;Schwarting et al, 2019;Wang et al, 2020;Siebinga et al, 2023), which all have potential to reduce accidents related to merging.…”