In this study, the transition of drivers’ states of attention from “excessive attention state” to “unfocused attention state” because of increasing time, existence of a leading vehicle, adaptability to driving conditions in different areas, such as urban or suburban environments, and decreasing tension was examined from the viewpoint of the drivers’ eye movements. The variability of the driver’s eye gazing was observed to gradually increase when a leading vehicle was present, i.e., the driver's process resource was concentrated on the leading vehicle at the beginning of the driving but on both leading vehicle and surrounding conditions before the end of driving. In addition, it was found that the difference between the unfocused attention state and excessive attention state was shown by the change in eye movement, depending on whether drivers were driving in urban or suburban areas. This shows that the driving conditions induced changes in the distribution of process resource.

driver attention state, eye gazing, eye movement, driving condition, process resource