Characteristics of Drivers’ Mental Workload in Tunnel Entrance Zones with Different Spatial Visual Conditions

Abstract

As engineers design and renovate roads, they must consider how road characteristics influence the mental workload of drivers and the corresponding safety of the roadway. We examined how the mental workload of drivers changed as they navigated through highway tunnel entrances with different spatial visual conditions. Thirty-two drivers with different familiarity with the experiment route participated in on-road experiment on real highway tunnels. We measured the eye movement and heart rate of participants to develop a mental workload model and analyze the variations in mental workload in different tunnel entrance zones. We found that route familiarity and spatial visual condition, specifically spatial intervisibility of the tunnel entrance, had significant effects on the mental workload of drivers, and a high level of familiarity with the driving environment may reduce the adaptation period to the tunnel entrance for drivers. The proposed mental workload model provides an efficient and innovative method for assessing drivers’ mental workloads.