Driving when distracted and sleepy : The effect of phone and passenger conversations on driving performance

This study investigates the effect of passenger and phone conversations on sleep-restricted driving. Six volunteers (50% male, mean age 24.8 +/- 4.3years) had their sleep restricted to 4h in bed followed by a 20-min simulated drive on three separate occasions. Each drive included either a passenger conversation, a mobile phone conversation or a quiet passenger. The effect size of a phone conversation on lane deviation was large while passenger conversation was small. The main effect of conversation on lane deviation was non-significant (F(2,10)=2.57, p=0.126). Combining sleep-restricted driving with conversations warrants further investigation.