The Time of Day Matters

Drowsy-driving crashes tend to be most prevalent when one would normally be sleeping.

Most drivers feel especially sleepy between midnight and 6am and, more surprisingly in the mid-afternoon between 1 pm and 4 pm. Even if you are well-rested before driving, your performance will still be poorer during these times, with performance dropping off steeply at 2am and 2pm during these periods. Furthermore, 7am in the morning is a very common time for drowsy driving crashes as people commence driving (often to go to work) before they are fully awake.

Many rush off to work in the morning before they are fully awake and have crashes, some of which are fatal.

So, even if you consider yourself the world's best driver if you are sleep deprived you should stay at home during these times.

Furthermore, if you normally have a "cat nap" in the mid afternoon best to avoid driving during this time !

Drowsy-driving crashes also tend to be more prevalent on a Friday, Saturday or Sunday. December is often the worst month for drowsy-driving crashes.

Drowsy-Driving & Travel

Sometimes it's unavoidable that people will drive in the early hours of the morning when they're normally asleep. For example, when they're catching or returning from an early flight or ferry trip. But even a short drive home can result in a drowsy-driving crash.

Drivers returning from long-haul flights, or coming off ships and ferries often drive home or try to reach a destination after having had very little sleep in the previous 24 hours. Even one alcoholic drink makes matters even worse, as it has been shown that on four hours sleep one beer can have the same effect on a drivers control and reaction times as a six pack of beer !


Anyone who has ever flown is likely to have experienced some degree of time zone change disorder, commonly known as Jet lag. Jet lag occurs when the body's biological clock is out of sync with local time. When travelling to a new time zone, our bodies are slow to adjust and remain on their original biological schedule for several days. The result is that we feel excessively sleepy during the day or wide awake at night.

Remember once again that even a short drive home can result in a drowsy driving crash.

It's illegal in Victoria, Australia

In Australia, the charge of 'Culpable Driving Causing Death' includes driving whilst fatigued*. The Crimes (Dangerous Driving) Act 2004 came into operation on 13th October 2004.

Drivers who fall asleep at the wheel and cause a fatal crash face up to 5 years in jail. However, if intent (ie; mens reas) is shown then drivers may face up to 20 years in jail.

' Don't drive when you're normally sleeping ' !

. and it's a big issue in some U.S. States

Some U.S. States have compulsory sleep apneoa blood testing for all drivers.

Front Seat Sleepers

A sleeping front seat passenger can be fatal. Research shows that drivers can pick up the sleep breathing patterns of their front seat passenger which can cause the driver to fall asleep at the wheel.

Black-out while driving

There are many undiagnosed and untreated sleep medical conditions in New Zealand such as narcolepsy, sleep apneoa, restless legs syndrome etc. These disorders can cause drivers to 'black out' without any warning especially if they are driving with less than six hours sleep the previous night.

Bright White Light

There is evidence to support that when you are tired the retina of the eye is down and a bright light can lead it to tell the brain to sleep, hence shutting you down unexpectedly.

'If you become drowsy, don't delay, pull over and stop in a safe place'.