Reliability of simulator driving tool for evaluation of sleepiness, fatigue and driving performance

To compare the impact of extended wakefulness (i.e., sleepiness) and prolonged driving (i.e., fatigue) at the wheel in simulated versus real-life driving conditions. Participants drove on an INRETS-MSIS SIM2 simulator in a research laboratory or an open French highway during 3 nocturnal driving sessions. A dose–response design of duration of nocturnal driving was used: a 2h short driving session (3–5 AM), a 4h intermediate driving session (1–5 AM) and an 8h long driving session (9 PM–5 AM). Two groups of healthy male drivers (20 for simulated driving and 14 drivers for real driving; mean age±SD=22.3±1.6 years), free of sleep disorders. Number of inappropriate line crossings, self-rated fatigue and sleepiness were recorded in the last hour of driving sessions to control the effects of prior waking time and time of day. Compared to the daytime reference session, both simulated and real driving performance were affected by a short nocturnal driving session (P