driving when tired

The fact that drunk, drugged and distracted drivers pose a danger to themselves and others is fairly well understood, but tired drivers, though often ignored as a risk, are every bit as dangerous.

The traditional image is of someone driving late at night, possibly on the way to or from a holiday, but these days, tiredness is often an issue with people driving for work too – often because of hours driven rather than the time of day.

If you spend the week working away from home or have just flown back into the country, you might also be susceptible to sleep related accidents.

Research carried out for the AA Charitable Trust’s #drowsydriver campaign, launched in November 2018, showed:

• One in eight (13%) UK drivers admit to falling asleep at the wheel
• Nearly two fifths (37%) say they have been so tired they have been scared they would fall asleep when driving
• Men (17%) are three times as likely as women (5%) to say they have fallen asleep at the wheel

What should I do if I start feeling tired when driving?

Winding down the window or turning the radio up aren’t effective at combatting tiredness. If you find yourself doing these things, it’s a sign you are sleepy and need a break. 

• At the first sign of tiredness, stop and take a break
• Stop in a safe place – don’t stop on a motorway hard shoulder
• Drink two cups of coffee or an equivalent caffeinated drink
• Take a short nap of around 15-20 minutes

How should I plan for driving a long distance?

Even experienced HGV drivers are prevented from driving more than 9 hours in a day or working for over 13 hours in a day. Most car drivers are nowhere near as used to driving for this long, so always keep these recommendations in mind if you're planning a long road trip.

• Don't drive for more than 8 hours in a day
• Take regular fifteen minute breaks in journeys over three hours
• Aim to stop every two hours or so, especially if you're not used to driving long distances
• Plan journeys so that you can take breaks, allowing for an overnight stay if necessary
• Don't start a long journey if you’re tired

What can increase the risk of driving tired?

• Heavy meals can make you sleepy
• Driving at times when you would normally be asleep brings extra risk, particularly the early morning
• Strenuous exercise before driving can also have a bad effect - especially for older people

What is the best way to sleep well?

According to Dr. Katharina Lederle, sleep scientist at Somnia author of Sleep Sense, the best countermeasure to sleepiness is sleep. It’s the only way to combat drowsiness and sleepiness. 

Sleep is what the body needs at this point because we have either been awake for a long time or our internal body clock is saying it is time for sleep. Sometimes these will both occur at the same time. 

• Loud music or cold air may raise our alertness for a very brief moment but does not address the fundamental need to sleep
• The risk of driver fatigue is highest between 2am and 6am, and again in the afternoon between 2pm and 4pm.  At these times, the internal body clock promotes sleepiness.

Some people will also be more prone to feeling sleepy at certain times of day – this is known as our ‘chrono-type’.

Dr Katharina Lederle’s Top Sleep Tips

1. Identify your personal sleep window: how much sleep do you need and when do you sleep best? Stick to these times weekday and weekend. 
2. Get out in the natural sunlight for about 30 minutes during the earlier part of the day – lunch from the café that is a little further away is where you want to go.
3. Having one or two coffees during the morning is ok (if you enjoy coffee), but then cut it out after lunch. Be aware that tea and energy drinks also contain caffeine!
4. During the day, take regular mini-breaks to reduce stress levels. You don’t have to wait for the evening to relax.
5. In the evening it is best to switch off your phone, tablet and laptop at least an hour before going to bed. (bedtime is often different to sleep time)
6. If you really need to use an electronic device in the evening, install a blue light filter and lower the brightness to reduce the light input.
7. Eat a healthy, balanced diet and keep regular meal times – meaning something for breakfast, lunch, and dinner. Avoid eating dinner too late in the evening.
8. Exercise regularly; and if done in the evening, allow enough time to wind-down.

Who is most at risk from driving tired?

Young drivers may be more at risk because they are more vulnerable to sleep loss and, depending on their age, tend to require more sleep than adults.

Young drivers may also suffer the effects of lifestyle choices such as excessive screen-time at night cutting into valuable sleep time, erratic sleep patterns and consumption of stimulants.

Our AA-Populus research shows:

• Young drivers, aged 18-to-24, are the most likely to say being very tired does not affect their driving ability (13% compared to 2% of all drivers)
• Young drivers are also the most likely to say they normally carry on regardless if they feel tired while driving (18% compared to 3% of all drivers).

In young people a brain area involved in decision-making has not yet fully developed and they may not be able to safely judge risks. They may shrug off the risk of falling asleep, or not consider it at all, and instead are overconfident in their ability to drive at any time of the day. This can have severe consequences on their ability to drive safely.

How does being tired affect driving?

If you don't get enough sleep it will affect your ability to function in several different ways any of which can have dangerous consequences when you're driving.  

Driving tired impairs judgement and reaction time so you may react slowly, brake late or miss a hazard altogether. This may explain why driving tired is a factor in a lot of rear end crashes.

Driving tired also affects your coordination so you might find yourself varying your speed - slowing down and speeding up -  or your lane position, rather smoothly following a straight line.

Crashes involving tired drivers are often at high speed and without any braking because the driver was asleep.

Is it against the law to drive while tired?

There isn't a specific offence of driving when tired but doing so significantly increases the chance of you committing other offences or causing a collision. The penalty for causing death by dangerous driving is up to 14 years imprisonment.

You must also tell DVLA if you have a medical condition that makes you very sleepy during the time that you would normally be awake. You could be fined up to £1000 if you don't and may be prosecuted if you're involved in a crash as a result.

Is it illegal to sleep in your car?

You can sleep in your car as long as you're legally and safely parked and are not under the influence of drink or drugs.

Watch out for local restrictions though, and bear-in-mind:

• Motorway service areas generally limit stays to a maximum of 2 hours and will fine you if you stay longer
• Many car parks close and lock their gates

Driving for work

If you're a company driver, you'll know how you can feel pressured into breaking guidelines to meet deadlines.

Most employers will have a road safety policy which should lay down rules to help prevent fatigue-related accidents.

Updated 2 November 2018