Feeling sleepy at the wheel is often framed in terms of having an undiagnosed condition, but what about those that just tend not to sleep well?

For these drivers the research should be a wake-up call.

An American university has found that compared to motorists who get seven or more hours of sleep each night, those who typically snatch just four or five hours are 5.4 times more likely to be involved in a crash.

Not only that but conservative estimates from the University of Alabama show that 21% of fatal crashes involve drowsiness.

This reflects UK research, which has found that almost 20% of accidents on the roads in this country are sleep-related.

Drowsy driving doesn’t sound nearly as dangerous as it should, a bit like ‘careless driving’ or ‘extreme car surfing’, but it’s a killer.

Drowsiness makes you less able to pay attention to the road, slows reaction times and can prevent you making correct driving decisions.

It’s more likely to result in a fatality or serious injury than other types of accident, with peak times occurring in the early hours of the morning.

According to Licence Check, commercial drivers are particularly vulnerable during this time of the day and there are two main reasons for that.

The first is down to scheduling and deadlines and a need to return the vehicle to base and the second is the lack of lorry parking facilities in this country along the road network.

But if you have an accident on the road while sleep deprived, you will be held accountable.

The penalty is one to 14 years in prison and disqualification for a minimum of two years.

Official advice includes having a high caffeine drink if you begin to feel drowsy, but this isn’t a perfect solution:

“The countermeasures that involve continuing to drive after noticing signs of drowsiness carry several risks,” explains Benjamin McManus, a PhD candidate at the University of Alabama.

“For instance, several alertness-enhancing activities may be distracting.

“Although caffeine and other stimulants reduce subjective sleepiness and improve reaction time, decision-making is still impaired.

“A cup of coffee or an energy drink may effectively increase alertness in a drowsy driver, but the driver is still at risk for driving errors and poor judgment.”

Like most things, the best solution to tiredness at the wheel is a good night’s sleep.

If you have committed a motoring offence contact our specialist motoring solicitors for advice on 0800 046 3066