# Situational Awareness Assessment of Drivers Boosted by Eye-Tracking Metrics: A Literature Review
## 3 Results
### Scientometric Analysis  
Based on the analysis of the 41 documents selected for full-text review and using the freely accessible software Bibliometrix version 4.1.4 [22], we described the growth trend of the study of SA with eye tracking in the field of driving in terms of citation and bibliographical information. The line chart in Figure 2 gives information on the annual scientific production in the study of SA based on eye tracking in the field of driving for the period 2011-2023. Annual scientific production over five years from 2011 remained steady, while it underwent an irregular fluctuation in the period 2016-2018. However, for 2018, we see a steady but remarkable rise in the number of articles. This is also seen in Figure 3, which shows the accumulated rise in the number of occurrences of the keywords \"SA\", \"eye-tracking\", and \"driving\" within the literature. Eye tracking related to the study of physiological measures of SA experienced a rapid surge in 2015 and reached a point of inflection in 2019. Moreover, out of the 41 selected documents, 29 were published in different scientific journals and 12 in conference proceedings. The most relevant sources are summarized in Table 1; _Human Factors_ and _Transportation Research Part F: Traffic Psychology and Behavior_ are the main journals in which the research was published. In all, 97% of the articles belong to quartiles of scientific journals Q1 and Q2, and the review included an average of 3.5 authors per document, with 40 multi-author papers and one single-authored article. Figure 3: Rise in the occurrences of keywords. Source: own elaboration using Bibliometrix. \begin{table}
\begin{tabular}{l c} \hline \hline
**Sources (Journal)** & **Articles** \\ \hline _Human Factors_ & 6 \\ _Transportation Research Part F: Traffic Psychology and Behavior_ & 5 \\ _Lecture Notes in Computer Science_ & 5 \\ _Accident Analysis and Prevention_ & 2 \\ _IEEE Intelligent Vehicles Symposium Proceedings_ & 2 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Most relevant sources (top 5) from among the 41 selected documents. Figure 2: Annual scientific production in the study of SA based on eye tracking in the field of driving. Furthermore, about 133 authors were devoted to the study of SA with eye tracking in the context of driving. The most relevant and cited authors who have contributed to this topic are [PERSON], [PERSON], [PERSON], [PERSON], and [PERSON] Furthermore, the number of citations of each article was reviewed to identify papers with major impacts; these papers include those of [23; 24; 25], with 358 citations in total. The most relevant affiliations and countries are listed in Table 2 and Figure 4, with Purdue University (USA) as the predominant institution, followed by the Delft University of Technology (the Netherlands), reporting on this topic. Only two studies originated from developing nations. Furthermore, we performed a keyword analysis. This analysis allows us to capture the fundamental content of the documents and aims to distinguish meaningful research topics in SA, eye tracking, and driving. A keyword co-occurrence network is shown in Figure 5. In this figure, the research topics are shown in the context of our literature review. In the plot, large circles represent the main keyword in the review, and the lines between keywords show the strengths of their correlation [26]. In Figure 5, four keyword clusters show the relationship among the main keywords, and synonyms and keywords with common meanings were identified in the review. The first category encompasses the examination of SA, delving into physiological measurement and the apprehension of driver behavior (indicated in red). Similarly, the second category pertains to eye tracking, encompassing driver behavior, pupillometry, and visual perception (represented in blue). The third category deals with driver gaze behavior, encompassing human-vehicle interactions and accidents (indicated in orange).