# Situational Awareness Assessment of Drivers Boosted by Eye-Tracking Metrics: A Literature Review
## 4 Discussion  
In this literature review, one of the principal aims was to investigate the objective assessment of situational awareness in drivers based on physiological metrics obtained through eye tracking. Our approach utilized a systematic literature review, and papers dealing with the assessment of SA in humans with eye tracking in the domain of driving were incorporated. Furthermore, our literature review encompassed a scientometric analysis, which identified prevalent authors and topics in the field. Similarly, we conducted a demographic analysis of the experiments and a compiled and comprehensive list of the eye-tracking metrics employed in these experiments. Additionally, we incorporated a compilation of experimental environments, classifying them into real (naturalistic) and simulated environments, and documented the primary devices utilized in these studies. The potential utility of gaze metrics in the assessment of SA was observed. Several explanations included in this review substantiate the robust relation between gaze behavior and SA, particularly within the context of driving activities that are characterized by their predominantly visual nature. These relationships are consistent with literature reviews such as that conducted by [9], where, among all the identified physiological measures, the eye-tracking technique is the most prevalent to assess SA. This alignment could enable the authors to explore how gaze behavior can signify various cognitive aspects of driver awareness and behavior, such as visual attention distribution, attentional patterns, distraction, remembered information, mental workload, decision-making, and prediction models of SA. Central to this understanding is the exploration of visual attention and attentional patterns inherent in the execution of complex tasks by individuals [8]. The first investigations of patterns in driving and visual attention with the use of eye trackers date back to the works of [PERSON] and [PERSON] (1970, 1972) using an eye-marker camera and a stabilization unit [11]. Reference [18] performed research on measuring attention in the visualization of the graphical interface in different industrial vehicles and reported that by measuring the pupil position and the duration and count of fixations on and off the screen, it is possible to observe the spatial awareness and monitor the points of attention of the operator. For example, ref. [29] investigated the use of mirrors for eye tracking during work at construction sites. Surprisingly, they found something different than expected: the operator spent less than 7% of his attention on the display. Studies on eye tracking open the door to obtaining objective information from the operator to make decisions regarding display design, for example, the use of head-up displays in the driver's line of sight and support training of the operators to increase the SA of the driver as demonstrated by [35], who reported that trained drivers had better performance and SA. Reference [24] performed a similar study and evaluated the visual attention distribution of drivers during automation and examined the influence of the scenarios around the driver on the increase in SA. These studies show that gaze fixation, pupil diameter, and saccades are the major metrics for predicting SA. As evidence, the study finds that a high number of fixations can be associated with the difficulty of gathering information, and additionally, saccade amplitudes are negatively correlated with SA, and the results have a high similitude to the study of [62]. The observations further underscore the intricate interplay between visual search patterns and error reduction. Similarly, ref. [47] investigated adaptable systems. They examined the effects of pre-takeover visual engagement on situation awareness during automated driving. Their results suggested that natural driving without previously marked tasks benefits drivers' SA more than asking drivers to pay more attention to the path when driving.