Driving tired as bad as being drunk

London: Driving for more than three hours without a break at night is like being drunk behind the steering.

Researchers found that tiredness after a few hours has the same effect as being over the drink-driving limit.

Even two hours of driving in the dark can affect performance so severely that it is the same as having a couple of drinks, the Journal of Sleep Research reports.

It is estimated that one-fifth of all accidents are due to sleepiness behind the wheel. One in three motorists admits to nodding off while driving at night, according to the Telegraph.

A study last year by experts at Cardiff University called for newly-qualified drivers to be banned from the roads at night, a move that could save 200 lives a year in Britain and result in 1,700 fewer serious injuries.

To assess the extent to which tiredness hinders driving performance, researchers at Utrecht University in the Netherlands recruited a group of healthy young men aged 21 to 25.

Under supervision, each one drove for two, four and eight hours at a time through the night. They had to maintain a constant 80 mph on the motorway and remain in the centre of their traffic lane.

After the experiment, they compared motorists' performances with what's already known about the effect alcohol can have on driver safety.

The results showed that after just two hours behind the wheel, the drivers were already making the same mistakes they would if they had 0.05 percent blood alcohol content - more than half the British legal drink drive limit of 80 mg of alcohol per 100 ml of blood.

At three hours, their performance corresponded to 0.08 percent blood alcohol content - the national limit and by four-and-a-half hours it was equivalent to 0.10 percent.