Road safety champions GEM Motoring Assist said the human body has developed a very efficient system of warning of impending tiredness and loss of concentration - long before you become drowsy and control of a vehicle is impaired.

The first signs of the onset of getting tired or bored are that the rate at which we blink goes up. An increase in the normal blink rate of about 10 blinks (also known as nictating) per minute is a warning signal that it is time to find an appropriate place to pull over and take a rest from the stress of driving. Blinking is a built-in early warning system that gives drivers the opportunity to head for the nearest motorway service area or other refuge from the road before their driving becomes erratic and potentially dangerous. It not only tells us that we are getting tired, but we are bored and liable to lose concentration.

Blinking is an essential body function that helps spread tears across the eye and removes irritants. It stops the eyeball drying out, kills bacteria and carries oxygen and nutrients to the corneal cells. A blink takes between 300 and 400 milliseconds and as a result humans lose about 23 minutes of visual information during a waking day.

"Making sure we are alert and as fresh as possible - especially on long journeys such as returning from holiday - is a critical element of road safety," said a spokesperson for GEM. "People should become much more aware of their blink rate and heed the warning if it starts to rise."

Wish I had known that after my eight-hour epic journey to Calais on Tuesday!

Jackie Violet - Female First