Does the Driver Understand the Warning? Comprehension of the Request to Intervene

Understanding the information conveyed by symbols is extremely important from the point of view of road safety. The symbols used on road signs and integrated into the vehicle must be clear and legible. This is especially important given the lack of regulations and standardization in the field of modern driving automation systems. Manufacturers are allowed to choose the way of informing the driver about the need to intervene in a situation when the vehicle is unable to continue driving in automated mode. The authors proposed to assess the comprehension of the information displayed by several different icons used to inform the driver about the need to take control. For this purpose, they used the adapted ISO 9186 Comprehension Test. The research was carried out on two different groups of drivers—passenger car drivers and professional bus drivers. A total of nine different pictograms were tested. The results indicate that drivers associate the red color with information about danger. The same icon in different colors may have a different effect on drivers, often leading to wrong responses.