Validating an Objective Roadside Tool to Assess Driver Fatigue

Fatigue has a known influence on negatively affecting driving safety (e.g., increased micro-sleeping, falling asleep at the wheel, and lane drifting) but has been difficult to detect and identify. As such, an objective and reliable roadside tool to detect driver fatigue is needed. The purpose of this project was to validate a series of assessment tests, including but not limited to the Critical Flicker Frequency (CFF), Brief Psychomotor Vigilance Test (PVT-B), and Trail Making Test, to determine their ability to reliably measure level of alertness or fatigue as an objective tool to assess driver fatigue. A large sample fatigue study was conducted to identify the rate and public acceptance of drowsy driving and establish normative data sets for select fatigue assessment measures among the general Minnesota population. Following that, a 30-hour sleep deprivation study assessed driving performance and fatigue under alert to extreme fatigue conditions. Results from the large sample fatigue study demonstrated a positive relationship between CFF threshold, age, gender, and elapsed sleep measures. Results from the sleep deprivation study showed prolonged wakefulness influenced driving performance (i.e., sleepiness at the wheel) and the relationship between impaired driving and cognitive test performance. A cognitive composite measure of the PVT-B and Trail Making Test predicted fatigue-related driving outcome variables, suggesting that these tests could be useful for further development and assessment of roadside measurement fatigue.