MANY motorists are putting lives at risk by driving for long periods while tired, according to a survey from the RAC.

Almost half (46 per cent) of drivers admit to taking to the wheel while feeling drowsy and a third have been close to falling asleep while driving, the survey found.

And 11 per cent have driven more than 500 miles in a single journey without taking a break.

The biggest risk-takers are men aged 35-64, with 20 per cent of all drivers completely unaware of the simple steps that can be taken to stay alert.

Almost 70 per cent of motorists think, incorrectly, that winding the window down can ward off sleepiness, while one in three believes turning up the stereo is the answer.

RAC road safety consultant, Robin Cummins, said: "Cars are more comfortable than ever and long journeys can lull motorists into a false sense of security.

"The dangers of drink-driving and speeding are well documented, but with driver sleepiness there's still some way to go, especially since drivers are using ineffective methods to prevent falling asleep at the wheel.

"It's crucial that we take the time to plan breaks and recognise when our bodies need a rest, to ensure we are capable of staying alert and able to concentrate to ultimately protect both our own, and other people's, safety."

Jim Horne, director of Loughborough University's sleep research centre, added: "Motorists who ignore the obvious signs of tiredness and push themselves to the limit are taking serious risks.

"They don't seem to realise that crashes involving falling asleep at the wheel are more likely to be fatal because of the absence of braking and greater speed at impact.

"Our studies have shown that drivers are particularly vulnerable in the small hours of the morning when the body clock is at its lowest, and especially on dull monotonous roads.

"There is also a 'dip' in the mid-afternoon, when the risk of these crashes is also higher.

"Motorists' increasing tendency to push themselves to the limit, because of work pressures, is again very worrying, and in this respect, employers should bear a greater responsibility in ensuring the safety of their staff."