Today is the first workday of Daylight Saving Time (DST) in 2019. FreightWaves Market Expert Dean Croke writes about the effects of the one-hour shift to DST and the deadly consequences it has over the short- and long-term. He also goes into the pros and cons of this supposed energy-saving practice.
Croke grew up in a family trucking business and spent years as an over-the-road truck driver and manager of large trucking fleets. He has combined his practical experience with extensive knowledge of human physiology, logistics and supply chain management to bring a unique perspective to this article.
Spring forward, fall back.
The second week of March is upon us which means all but two of the 50 states (Arizona and Hawaii) shift their clocks forward an hour to what’s known as daylight saving time (DST). This happened at 2:00 a.m. Sunday morning, so everyone “lost” an hour of sleep before they woke up Sunday morning. Even though it’s only one hour, the disruption to sleep patterns, sleep deprivation and decreased alertness levels result in higher rates of fatal accidents which increase 17 percent along with heart attacks which jump 25 percent on the Monday after the shift to DST. (That’s today!!!)
In a 2014 fatal crash study conducted by the University of Colorado at Boulder, it was concluded that beyond the increased fatal accident risk on the first day of daylight saving, there was also a 6.3 percent increase in fatalities over the first six days, causing 302 deaths at a social cost of $2.75 billion over a 10-year period.
There are ongoing debates about the benefits of DST, but losing an hour of sleep creates significant consequences for all drivers.
The Pros and Cons of Daylight Saving
Depending on who you talk to you, you’ll most likely get a very mixed reaction to the benefits of DST. It has been around for over 100 years, but with little evidence to substantiate the original energy savings resulting from DST. With more recent evidence pointing to adverse health effects from the twice-a-year time change, many ask why it still exists. In fact, that question was posed by the European Union Commission in an online survey in August 2018 – 80 percent of the 4.6 million European respondents voted in favor of abolishing DST in 2019, citing negative consequences to human health as one of the main reasons. In a 2016 survey conducted by The Finally Light Bulb Company, 49 percent of respondents said they don’t like losing an hour of daylight in March, and 63 percent also felt sleepier, with 25 percent feeling more lethargic after the clocks turn back in November each year.
The original idea behind DST was to have more daylight in the evenings and less in the morning; in the process reducing energy consumption by increasing the amount of natural light. People opposed to DST suggest it has outlived its usefulness with the rapid advancement of energy-saving technologies including “smart lighting” such as LEDs (light emitting diodes), which use about 75 percent less energy when compared to traditional incandescent light bulbs. Smart cities, smart buildings and smart devices have also made a big impact on reducing energy consumption, so why do we still have DST if less than 40 percent of the countries in the world use it?
Proponents of DST argue that more time in the evenings allows people to do more after work, and in the process develop a healthier lifestyle by participating in sports including running, baseball, soccer and golf to name just a few. The other big beneficiaries are the retail and restaurant sectors, whose profits get a boost from longer evenings allowing people to shop and eat out more often. Communities are also safer with one study showing a seven percent decrease in robberies after DST is implemented.
Employees at Buckingham Palace and Windsor Castle in London are one group that loves DST, according to the Royal Collection Trust. Following months of planning, staff members begin work in the early hours of Saturday morning to ensure that by Sunday evening, the have manually adjusted close to 900 historic analog clocks. Of course these days most of us have digital clocks that automatically adjust to DST.
Fatal Accidents and Injuries Rise in Summer for Truckers
Losing an hour of sleep does not seem like a big deal to most non-shift workers, but to an already tired trucker, the impact of daylight saving time is always significant, and sometimes deadly. This week in particular, things will be especially tough for truckers as their bodies adjust the new timing of light and dark.
As we head into Spring we are seeing signs that freight volumes are increasing with truckers running more miles and working more hours each day. In the last two weeks, freight volumes (SONAR: OTVI.USA) have risen six percent along with driving hours (SONAR: HOS11.USA) also increasing over two percent – this is good news and bad news for truckers.
The good news is more miles and hours means more pay; the bad news is that on top of losing an hour of sleep following the DST shift, is that it’s dark when drivers are commuting to start the day shift, but most importantly, sunset now happens later in the evening, delaying sleep onset and truncating sleep in the process. This impacts everyone, but for truckers, the effect is amplified given their non-traditional work schedules, inconsistent start times, long work hours and cumulative fatigue.
The fatal accident and injury rate for commercial truckers start to rise as we move out of winter when there’s more dark than light (more time to sleep), and into the warmer spring and summer months when there is much more daylight (less time to sleep). The chart below (SONAR Ticker: FATL.USA) highlights this counter-intuitive trend in which commercial vehicle fatal accidents rise 30 percent on average between March and the end of summer.
So what, now what?
Sleep is not a complicated process – we’re designed to go to bed when the sun goes down and wake when it comes up. Anytime we extend sunlight later into the evening we’re simply delaying sleep onset through the abundance of ambient light (particularly blue light), which is the brain's primary cue to be awake. Put simply, the “sleep gate” won't open if the eye can still sense daylight (unless of course there’s a bad case of sleep deprivation at work); DST simply exacerbates the situation.
The physiology of sleep tells us that humans are hardwired nocturnal sleepers and even though there are hundreds of circadian rhythms (24-hour cycles) that drive the sleep-wake process, light, and in particular blue light, is the single most influential factor in determining when we sleep and wake. This is why the shift to DST has such a profound impact, as the timing of blue light to the optic nerve shifts one hour.
Hurry up and wait
Drivers and fleet managers also have something new to contend with as drivers have more evening daylight on their hands, and that’s the increasing amount of time they spend on docks loading and unloading freight. The chart below highlights the problem. As capacity has loosened since July 2018, we can see the rate of outbound tender rejections (OTRI.USA) has dropped 71 percent to a low of 7.25 percent this week. In contrast, the number of detention minutes per loading and unloading event (WAIT.USA) has risen 23.25 percent over an eight-month period, and in just the last four weeks it has jumped 18 percent as capacity has increased.
This suggest shippers are taking longer to unload and load, and with electronic logging devices requiring a drivers’ duty status to be set to “on-duty/non-driving” during dock time, technically they are in control of their vehicle and therefore not allowed to sleep. Of course the exceptions would be when shippers ask the driver to drop the trailer and leave the premises allowing the driver to switch duty status to “off-duty.” For drivers in the “live” load and unload freight market, especially in food and beverage, their timing and duration of sleep is severely disrupted as detention minutes climb, and in the process this drives up the risk of accidents and injuries – not to mention the stress created through lost productivity and lower pay.
With the risk of accidents and injuries climbing early this week and lasting until the end of summer, fleet and safety managers should be in immediate contact with all of their drivers and shippers to make allowances for the disruption to driving schedules and sleep patterns caused by the shift to DST.
It’s only an hour, but the risk and long-term accident and health consequences of DST last much longer.