## 3 Analysis of Current Knowledge
### Applications of the Eye Tracking Method
The aim of this study [20], already mentioned above, was to assess the effect of these LED advertising devices on visual behavior and driving performance. A total of 41 drivers were interviewed and asked to drive an instrumented vehicle on a stretch passing four of these LED advertising devices under day and night conditions. Distraction by visual perception was found if the driver looked at the advertising message continuously for two seconds or if they took their eyes off the road for a percentage of the time. The dependent variables were eye movement (measured by the aforementioned eye-tracking method) and driving performance. Based on the visual behavior data, it was found that drivers had significantly longer gaze fixation times, a higher number of gaze fixations and a longer maximum gaze fixation time when passing near LED advertising devices compared to other sources of visual perception on the same road. No differences were observed in relation to day/night factors and no effect on driving behavior data was found. LED advertising devices have an effect on gaze direction and duration (gaze behavior) as they attract more frequent and longer gazes than conventional road signs. It can be noted that the LED advertising devices caught more visual attention than the other types of road markings included in the study. In the case of LED advertising devices, longer dwell time, higher visual attention share, more frequent very long gazes and higher number of gaze fixations were observed. As the information on the LED advertising devices changed at regular intervals, the displayed messages had the potential to sustain drivers' interest for a longer period of time. Studies of the impact of advertising devices on driver behavior have generally shown that their presence has negative consequences on several levels: drivers' observation capacity is reduced (they look away from the road more often and for longer periods of time), reaction time is increased (drivers react more slowly to important signals under the influence of advertising messages) and the quality of vehicle control is reduced (they deviate from the direction of travel more often). These adverse effects are more likely to occur in the presence of moving advertisements, or if the surfaces are located in the central field of view, contain emotionally important information or resemble road signs or traffic information panels. Moreover, in an environment saturated with visual information, important traffic-related information is often lost. At the same time, dynamic advertising devices have been found to have an impact on gaze behavior, as they catch people's eyes more often and for longer periods of time than standard traffic signs. This clearly shows that they impair traffic safety. However, all the studies discussing the issues of the advertising device do not specify the risk of the object in question, but only point to the risk associated with distraction of the driver's attention. On the basis of the knowledge gained, it is possible to implement a similar principle of testing, on the basis of which it will be possible to create a risk scale and define the severity of individual advertising devices in general.