L4 – Fitness to drive

Before setting off on a journey, responsible drivers consider both their personal fitness to drive and their vehicle’s fitness for the road. When it comes to our personal fitness to drive, usefully there’s a mnemonic to remind us of key considerations – AM I SAFE?

According to Roadcraft (the police driver’s manual), attitude “is the state of mind with which [we] approach the driving task.” Whilst some attitudes are conducive to safety, others – like impatience, intolerance, and impulsiveness – compromise safety.

Roadcraft provides some practical suggestions for countering unhelpful attitudes and behaviour:

  • concentrate on applying the lessons of this course, not on what another road user has just done. Whilst we can’t control others, we can and should exercise self-control
  • focus on the task of driving defensively rather than what awaits you at your destination
  • avoid ‘personalising’ other drivers, in thought or speech. No one is really out to get you, you know!

In the UK and, no doubt, many other countries, it is illegal to drive if our ability to do so may be impaired by drugs, including those prescribed by our GP. If in doubt, we should therefore check with our doctor or pharmacist.

Whether we’re taking medication or not, illnesses and ailments can compromise our fitness to drive. During involuntary bouts of sneezing due to pollen or dust, for example, we’re blinded by our eyes reflexively closing. During persistent bouts of sneezing or coughing, what could we not see? Perhaps a child wandering into the road.

Driving whilst tired
Drowsy driving alone is worse than driving drunk

Every hour, someone dies in a traffic crash in the US due to errors related to fatigue.

According to sleep scientist Professor Matthew Walker, “drunk drivers are often late in braking and late in making evasive manoeuvres.” In his book, Why We Sleep, Professor Walker points out that when we fall asleep, or nod-off into a momentary ‘microsleep’, “[we] stop reacting altogether.”

Before setting off – particularly prior to non-local journeys – we should consider whether we’re well-rested. During any journey during which we begin feeling drowsy, we must stop at the first safe opportunity. Professor Walker suggests “a brief nap (twenty to thirty minutes).” He also cautions against driving immediately on waking, due to ‘sleep inertia’. “Wait for another twenty to thirty minutes, perhaps after having a cup of coffee if you really must, and only then start driving again.”

During the morning after a night on the town, we would do well to consider if we might still be impaired by residual alcohol, and consequently not fit to drive.

Food & water
Have you experienced a so-called food coma after eating a heavy lunch? Whilst related research is ongoing, the best advice from the researchers is to eat small meals. This seems especially true at lunchtimes if we’re to drive shortly afterwards. But starving ourselves isn’t the answer – caffeine or cake cravings might help to keep us awake but they can also be distracting.

If we don’t consume enough fluids, over time our bodies will become dehydrated. According to the British Nutrition Foundation, “studies have shown that at about 1% dehydration (the equivalent of 1% of body weight water loss) there are negative effects on mental … function and these become more severe as dehydration gets worse.” One of the symptoms of mild dehydration is poor concentration.

To remain alert, we need to be satiated and hydrated. But how can we tell if we’re adequately hydrated? Back to the BNF: “When the body detects that more water is needed the first thing that happens is that the kidneys reduce the amount of water lost in the urine. This means that the colour of the urine becomes darker and you can use the colour of your urine to tell if you are well hydrated – if you are drinking enough your urine should be a straw or pale yellow colour.”

Who would have thought that the answer is in the toilet?

Given our emotional state could trigger problems – for example, anger triggering sometimes deadly road rage – it’s perhaps best to not flee an argument or stressful meeting by spinning wheels away from the scene. Taking some mindful moments – a breather – before setting off might help to steer us away from trouble.

Whilst AM I SAFE? is a useful checklist for considering personal fitness to drive, what about checking on our vehicle’s roadworthiness? We have you covered.

POWERED is a handy reminder of important, periodic pre-drive checks.

Do I have sufficient fuel to complete my journey with a reasonable reserve for the unexpected?

When did I last check the oil level?

Advanced driving course
The higher our mileage, the more frequently we should dip the stick

Is there enough coolant and windscreen wash? Did you know that it is an offence in the UK if your vehicle is fitted with a windscreen washing facility for it to be empty?

Are all my lights and signals working? Whilst in some vehicles lights are monitored functions, with a warning appearing on the dashboard if something is wrong, in some older vehicles especially, we will need to check with a walkaround.


How are the tyres’ pressures and tread? In the UK, car tyres must have at least 1.6mm of tread across the central three-quarters of the tyre’s width and around the whole circumference. However, in wetter climates – yep, we’re alluding to the UK again! – it is best to not go that low. Below 3mm of tread, the risk of aquaplaning is much higher.

Aquaplaning is a loss of control that occurs when a vehicle’s tyres rise away from the road surface on a wedge of water, due to the tread’s inability to cope with the volume of surface water it is driving through. Much like how a speedboat’s hull rises out of the water at speed and then merely skims the surface, our vehicles’ tyres can do the same after rain.

Do I have the equipment to deal with a puncture and do I know how to use it?

Damage & defects
During a walkaround, we can look for damage to our vehicle’s windows and panels, and for fluids that have leaked onto the ground. This is particularly important prior to signing for a rental vehicle or company pool vehicle, otherwise we might be held responsible for pre-existing damage.

Whilst this lesson has provided a couple of checklists for ensuring fitness to drive, in the next lesson we will explore the importance of being systematic on the approach to each and every driving hazard that we encounter on the world’s roads.