The number of motorists driving when tired has soared in recent years, it has been disclosed.
As many as 74% of drivers admitted to getting behind the wheel when feeling sleepy in the past 12 months, a survey by road safety charity Brake and insurance company Direct Line found.
This is a big rise on the figure for six years ago which showed that 46% of motorists owned up to driving when tired.
The Government advises drivers on long journeys to take breaks every two hours, yet the Brake/Direct Line survey found that 73% of the 800 drivers polled drove for three hours or more at a time.
The survey also showed that more motorists (70%) drove with a window open to stave off sleep than took regular rest breaks (69%).
Also, while 54% had a radio on or listened to CDs to keep alert, only 21% had a nap at a rest break.
Brake's campaigns officer Ellen Booth said: "It is terrifying how complacent drivers are about tiredness at the wheel. It only takes a couple of seconds of sleep to cause a fatal crash, yet millions of drivers are regularly getting behind the wheel while tired, and most don't know how to deal with sleepiness on a long journey.
"We all know when we're feeling sleepy - we know what the warning signs are. When we're driving we must listen to these signs without delay. Thinking that we can fight off sleep, especially using unproven methods like opening the window, is a mistake that could cost your life, or someone else's."