Measuring driver awareness based on correlation between gaze behavior and risks of surrounding vehicles

We investigated a method to estimate the degree of driver awareness of surrounding vehicles based on the correlation between driver gaze direction and the risks caused by surrounding vehicles. The risks posed by surrounding vehicles were represented by their time to collision (TTC) from the driver´s vehicle. We recorded driving data from five expert and five non-expert drivers while passing other vehicles on expressways, using an instrumented vehicle. We manually labeled the drivers´ gaze directions using video of the drivers´ faces, and detected the positions of surrounding vehicles and calculated TTC using laser scanners mounted on the front and back of the vehicle. We focused on driver´s gaze behavior for five seconds before the driver began moving into the right hand lane at the beginning of the passing maneuver and calculated the correlation index between vectors representing the distribution of gaze resources and risk levels of surrounding vehicles for eight zones around the vehicle. We found that there were individual differences in gaze behaviors, and that expert drivers showed a higher degree of awareness than non-expert drivers.