Prolonged night driving unsafe

Prolonged night driving unsafe
11 Jun 2008, 1229 hrs IST, IANS

WASHINGTON: Prolonged driving at night impairs performance at the steering wheel and should be discouraged, according to a new study.

The study focussed on 14 healthy youths who drove in three nocturnal sessions (3-5 am, 1-5 am and 9 pm to 5 am) on an open highway.

Researchers monitored inappropriate line crossings in the last hour of driving of each session, sleep variables, self-perceived fatigue and sleepiness.

As compared to the 3-5 am driving session, the ratio of inappropriate line crossings increased by 2.6 in the 1-5 am session and by a factor of four in the 9 pm-5 am driving session.

Self-related fatigue and sleepiness scores were both correlated to driving impairment in the 1-5 am and 9 pm-5 am driving sessions and increased significantly during the nocturnal driving sessions compared to the reference session.

"Until now, regulations have taken into account maximal duration of driving, but the cumulative effects of sleepiness and fatigue were never studied or integrated in the driving regulation," said Pierre Philip of Université Bordeaux in France, co-author of the study.

"Here, we show that performance is badly affected by time of the day, and therefore, we think that a warning to limit maximum nocturnal driving duration should be included in professional safety recommendations."

The findings of the study were presented Tuesday at 'SLEEP 2008', the 22nd Annual Meeting of the Associated Professional Sleep Societies.