One eighth (13%) of UK drivers admit to falling asleep at the wheel, according to an online poll of 20,561 drivers by the AA Charitable Trust.
The survey also revealed a further 37% had, at some point, been so tired they had been afraid they would fall asleep while driving.
Government road casualty statistics demonstrated that tired drivers contributed to 53 fatal and 351 serious crashes in 2017.
However, the AA Trust said the real figure for fatigue-related incidents is likely to be much higher due to under-reporting. It is estimated that up to 25% of fatal accidents may be caused by drivers who are asleep at the wheel.
The research was conducted as part of a new national campaign, created by the AA Trust and FIA Foundation, alerting motorists to the dangers of driving while tired.
AA Charitable Trust director, Edmund King, said: "One quarter of fatal crashes are sleep-related, so drowsiness is one of the most under-estimated risks on the roads.
“Tiredness is a fact of life at some point for most of us and it is crucial we know how to manage it in relation to driving.
“Crashes involving a drowsy driver tend to be catastrophic. If a driver has fallen asleep at the wheel they do not brake before an impact and make no attempt to steer away from a collision.
“A driver who nods off for just three or four seconds on a motorway would have covered the length of a football pitch with closed eyes. A 30-second nap while travelling at 60mph covers half a mile; a terrifying thought.
“Simple measures can help alleviate the risks. Awareness of the problem is the first step, which is why we have launched this campaign and created an advert highlighting the dangers.
“Winding down the window, singing and turning up the radio are not remedies to tiredness – rather a symptom in themselves.
“If you feel tiredness creeping up on you when driving then stop and take a break.”
Dr Katharina Lederle, sleep expert at Somnia, added: “The simple truth is the only long-term cure for sleepiness is sleep and drivers are not able to fight it off by opening the window or turning up the radio.
“Drinking caffeine and having a short nap before the caffeine effect kicks in - about 20 minutes - is a short-term solution.
“It can help drivers increase their alertness sufficiently to carry on driving for another hour or two. But this is no substitute for proper sleep.
“There are certain times of day when the risk of driver fatigue is highest, specifically between 2am and 6am and 2pm and 4pm, when the internal body clock is promoting sleepiness.”
