Effects of In-vehicle Information on Driver Eye Blink Duration and Workload

A real-vehicle experiment was conducted to study the effects of in-vehicle information systems on driver workload. Data of driver blink duration and frequency were collected with in-vehicle equipment mounted at three different positions. Driver blinking characteristics were studied for the navigation system providing image route information or image and sound route information. The distributions of blink duration and count with and without using route navigation were compared. Experimental data show that the blink count has dramatic bimodal distribution when blink duration ranges from 0 to 200 ms with an interval of 10 ms. Without using route navigation, blink counts between 50 and 60 ms are lower than those between 10 and 20 ms, while the results are converse using route navigation. The positions of navigation system return no significant effect in the counts of medium and long blinks while return significant effect on short blink count. Without sound route information, the double peak values of blink count are larger than the case with sound route information. Besides, short blink counts increase most noticeably, and then medium blink counts, while long blink counts nearly remain constant. This demonstrates that using the navigation system increases driver mental workload, and when the navigation system is mounted on the stands, the workload is the minimum. With sound route information, the workload is decreased.