Fatigue, sleep restriction and driving performance.
Accident Analysis & Prevention. 2005-05-01; 37(3): 473-478
DOI: 10.1016/j.aap.2004.07.007
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1. Accid Anal Prev. 2005 May;37(3):473-8.
Fatigue, sleep restriction and driving performance.
Philip P(1), Sagaspe P, Moore N, Taillard J, Charles A, Guilleminault C, Bioulac
B.
Author information:
(1)Clinique du Sommeil, CHU Pellegrin, Place Amelie Raba Leon, 33076 Bordeaux
Cedex, France.
We ran a randomized cross-over design study under sleep-deprived and
non-sleep-deprived driving conditions to test the effects of sleep restriction on
real driving performance. The study was performed in a sleep laboratory and on an
open French highway. Twenty-two healthy male subjects (age = 21.5 +/- 2 years;
distance driven per year = 12,225 +/- 4739 km (7641 +/- 2962 miles) [mean +/-
S.D.]) drove 1000 km (625 miles) over 10 h during five 105 min sessions on an
open highway. Self-rated fatigue and sleepiness before each session, number of
inappropriate line crossings from video recordings and simple reaction time (RT)
were measured. Total crossings increased after sleep restriction (535 crossings
in the sleep-restricted condition versus 66 after non-restricted sleep (incidence
rate ratio (IRR): 8.1; 95% confidence interval (95% CI): 3.2-20.5; p < 0.001)),
from the first driving session. The interaction between the two factors
(conditionxtime of day) was also significant (F(5, 105) = 3.229; p < 0.05).
Increasing sleepiness score was associated with increasing crossings during the
next driving session in the sleep-restricted (IRR: 1.9; 95% CI: 1.4-2.4) but not
in the non-restricted condition (IRR: 1.0; 95% CI: 0.8-1.3). Increasing
self-perceived fatigue was not associated with increasing crossings in either
condition (IRR: 0.95; 95% CI: 0.93-0.98 and IRR: 1.0; 95% CI: 0.98-1.02). Rested
subjects drove 1000 km with four shorts breaks with only a minor performance
decrease. Sleep restriction induced important performance degradation even though
time awake (8h) and session driving times (105 min) were relatively short. Major
inter-individual differences were observed under sleep restriction. Performance
degradation was associated with sleepiness and not fatigue. Sleepiness combined
with fatigue significantly affected RT. Road safety campaigns should encourage
drivers to avoid driving after sleep restriction, even on relatively short trips
especially if they feel sleepy.
DOI: 10.1016/j.aap.2004.07.007
PMID: 15784201 [Indexed for MEDLINE]