The clocks skipped an hour over the weekend in Victoria and NSW, as Australia’s two most populous states started daylight savings ahead of summer.
Do interrupted sleeping patterns and longer daylight have an impact on road safety?
There is no clear evidence directly linking the changing time zones with an increase in fatal or serious injury crashes, but experts in Australia and the US are increasingly of the view that changing our “body clocks” could lead to fatigue-related crashes and poor decision making.
Daylight savings in Victoria and NSW historically commences in the first week of October by moving the clock forward one hour, therefore losing one hour’s sleep.
National road toll data for Australia over the past 10 years shows there is, on average, a 9 per cent increase in fatal crashes in October compared to September.
The national average road deaths every October for the past 10 years is 104, versus an average of 95.4 deaths recorded every September over the same period.
However, daylight savings cannot be solely to blame for this discrepancy because October also has school holidays and a long weekend in some states, and figures show deaths increase during such periods due to driver fatigue and increased long-distance travel.
It is worth noting that while there were increases in the number of road deaths when comparing the months of September and October in seven of the past 10 years, there were three years in which road deaths declined in October versus September (2011, 2017 and 2018).
Crash investigators say road conditions and adverse weather are major factors in road deaths, as are alcohol, drugs, excessive speed, and occupants not wearing seatbelts.
A report out of the US published in February this year said in part: “There is evidence that the spring daylight saving time transition acutely increases motor vehicle accident risk, which has been partly attributed to sleep deprivation and circadian misalignment (the human “body clock”) … because mornings are darker and evenings brighter, changing illumination conditions for peak traffic density.”
The US report noted the change in road behaviour was most evident in the days that followed a time change, rather than an entire month. However, publicly available road toll data for Australia only lists statistics month by month.
Sean Cain, an associate professor of psychology from Melbourne’s Monash University, and a “chronobiologist” (a scientist who studies timing processes such as circadian rhythms in humans) told The Sydney Morning Herald:
“It’s not like this is a massive problem and you have thousands and thousands of people dying in Australia because of it – we would have picked that up,” Professor Cain told The Sydney Morning Herald.
“But more and more of the research is showing that living in daylight saving time is a little bit unhealthy. And when you take something that is a little bit unhealthy and put it on a population scale it can affect a number of people.”
National road deaths October versus September over the past 10 years:
2019: 99 versus 91
2018: 74 versus 101
2017: 94 versus 100
2016: 118 versus 90
2015: 122 versus 87
2014: 108 versus 94
2013: 96 versus 83
2012: 118 versus 110
2011: 91 versus 93
2010: 120 versus 105
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