People generally need between seven and eight hours of continuous sleep every night to ensure that they are well rested and able to feel refreshed.
However if someone is regularly getting poor quality sleep, or insufficient hours this can build up a sleep debt over time that can seriously affect a truck driver’s ability to function safely at work.
According to the NTC (National Transport Commission) at their website http://www.ntc.gov.au/ the following are the principal causes of fatigue:
Working in the transport industry can be demanding. Common work practices for many drivers include working long hours, prolonged night work, working irregular hours, little or poor sleep and early starting times or late finishes. A working week of over 70 hours is standard for many drivers. These long hours of work can result in less than adequate sleep and a tendency towards ongoing fatigue. This situation is not acceptable to the wider public and is not in the interest of the transport industry itself.
Our biological clock
As well as sleepiness being caused by sleep debt, everyone has a biological clock that influences how alert or sleepy we are at certain times of the day. As humans, we are designed to be awake in the daytime and asleep at night (circadian rhythm). We also naturally experience sleepiness during the mid-afternoon “siesta hours”.
Our body temperature drops to its daily low point at these times of the day (midnight to 6 a.m. and 2 p.m. to 4 p.m.) as our body naturally slows down to sleep. The risk of being involved in a crash increases when driving during these natural ‘lulls’ when the body has a natural tendency towards sleep. With inadequate sleep the sleepiness experienced during these natural ‘lulls’ can be a lot stronger and can have an even greater negative effect on a driver’s performance and alertness.
Driver health and sleep disorders
Poor health and inactivity can make us feel tired and fatigued. Health issues may include diet, obesity, fitness and alcohol and other drugs. Sleep disorders such as sleep apnoea, which seems to be relatively common amongst truck drivers, cause poor sleep and result in fatigue. Symptoms of sleep apnoea include heavy snoring broken by sudden periods of silence, restless sleep and constantly being tired during the day. Drivers who think they may be suffering from sleep apnoea or any other sleep disorder may be a risk to themselves and to other road users.
Drivers must see a doctor for advice on the proper review and treatment of sleep disorders. refer to the Assessing Fitness to Drive 2003 guidelines (Austroads, 2003) and the requirement for continuing employment as a commercial heavy vehicle driver.
Driver fatigue is a serious issue. Often people that are suffering from fatigue are not aware that they are seriously affected which is why it is essential for everyone in the supply chain to work together to combat this issue.