PRESS ASSOCIATION -- As many as one in eight drivers has "nodded off" at the wheel in the past year, a survey shows.
And 29% of drivers have continued their journey despite noticing the first signs of drowsiness, according to the survey by road safety charity Brake and weight management programme Cambridge Weight Plan.
The one in eight figure refers to drivers who have nodded off for between two and 30 seconds, often without realising they have been asleep.
The poll of 1,000 drivers also showed that a quarter admitted starting journeys when already feeling tired.
A total of 86% were failing to follow advice to stop somewhere safe for a nap when getting tired at wheel.
In addition, 13% reported suffering from a health condition such as sleep apnoea that makes them tired during the day. Sleep apnoea can cause daytime sleepiness, and in some cases can cause the sufferer to fall asleep without warning.
The survey results were presented at a parliamentary reception attended by MPs, road safety experts and civil servants.
Experts estimate that tired drivers cause one in five fatal crashes on motorways. Crashes caused by drivers falling asleep at the wheel tend to be high-speed ones, as drivers do not brake before crashing, so the risk of death or serious injury occurring is greater than in other types of crashes.
Brake campaigns director Julie Townsend said: "Tiredness at the wheel kills. Driving a vehicle is a huge responsibility that must be taken seriously. That means stopping when we feel drowsy and certainly never starting a journey tired. It's a matter of life and death.
"We still have widespread misunderstanding of how to prevent driver tiredness, and ignorance about factors like sleep apnoea, a condition that can be treated. These messages still need to get through to the public, which is why we are calling for renewed efforts from the Government to tackle this issue urgently."