Detecting driver stress and hazard anticipation using real‐time cardiac measurement: A simulator study

Abstract

Objectives: In the context of growing interest in real-time driver stress detection systems, we question the value of using heart rate change over short time periods to detect driver stress and hazard anticipation. Methods:To this end, we explored changes in heart rate and speed as well as perceived stress in 27 drivers in a driving simulator. Driver stress was triggered by using hazardous road events, while hazard anticipation was manipulated using three levels of hazard predictability: unpredictable (U), predictable (P), and predictable and familiar (PF). Results:The main results indicate that using heart rate change (1) is a good indicator for detecting driver stress in real time, (2) provides a cardiac signature of hazard anticipation, and (3) was affected by perceived stress groups. Further investigation is needed to validate the lack of relationship between increased anticipation/predictability and strengthened cardiac signature. Conclusions:These results support the use of heart rate change as an indicator of realtime driver stress and hazard anticipation.

Exploring hazard anticipation and stress while driving in light of defensive behavior theory

“…Indeed, all cues were delivered a few seconds after exiting a turn. This hypothesis is further reinforced by the fact that the study that inspired our research 45 did not show such cardiac fluctuations in the control condition, probably because the exploration of the cardiac response was performed in a straight line, away from any turns. In addition, because simulator driving was a relatively new activity, cognitive and motor efforts might have been magnified due to poor vehicle control in the simulated environment.…”

“…This observation is in line with previous studies reporting fear bradycardia 48 , 49 during threat anticipation and interpreted as a parasympathetic physiological indicator of freezing behavior 38 , 50 . Based on previous work exploring freezing with active coping opportunities in driving 45 and non-driving contexts 28 , 30 , the freezing behavior expressed by the drivers in this study could be considered as a state of “active preparation” for subsequent flight behavior. In the same way that freezing should not be confined to a purely passive state, a recent research reported that a state of preparedness, similar to freezing, facilitated perceptual decision 43 .…”

“…All participants faced three experimental conditions: a safe condition (False alarm; F) involving a hazard cue with no hazardous event, and two hazardous conditions—one in which the hazardous event occurs unpredictably (Unpredictable; U), and the other in which the hazardous event is signaled by a hazard cue (Predictable; P). It should be noted that the choice of cue and event was inspired by a recent study 45 in which hazard anticipation and stress were successfully manipulated using this same type of cue and event: Hazard cue The cue was depicted by an alert message that popped up on a simulated phone located on the windshield. For the P and F conditions, the cue was visible to drivers (i.e., Cue ON) until the hazard appeared, in order to generate hazard anticipation.…”

“…To broaden the understanding of processes and behaviors in hazard anticipation and stress, we encourage future studies to use a similar methodology to explore other cues and road hazards. Previous studies have examined different hazardous situations using a similar methodology; however, they are still few in number 45 , 68 . We also encourage the exploration of cues, for example, by varying the duration of their presentation to drivers.…”

How are Drivers' Stress Levels and Emotions Associated with the Driving Context? A Naturalistic Study

“…Recent developments in ubiquitous computing devices such as smartwatches are facilitating their applications in detecting unhealthy states of the users such as abrupt changes in anxiety, stress level, and experiencing negative emotions at both individual and community level [10], [11]. Using ubiquitous computing devices, studies have found strong correlations between human psychophysiological measures (e.g., HR and skin conductance) and stress level and work load, and more specifically in driving, studies show that increase in human HR might be correlated with stressful experiences [12], [13], [14], [15], [11].…”