FreightWaves Market Expert Dean Croke: Science of sleep, part two

Allowing drivers to put together their 11-hour on-duty and 10-hour off-duty blocks however they see fit is key. As long as the numbers add up to 11 and 10 at the end of a 24-hour period, there should be no issues as to how they work it out. This is why drivers want the 30-minute rest break at the eight-hour mark dropped, since they are already taking that break as they wait around on loading docks. They also want the 14-hour clock workday limit expanded or dropped to accommodate their sleep preferences.

There have to be some guard rails for drivers with this approach since the number-one risk factor for severe accidents is a variation in the day-to-day start time. The flip side of fluctuating start times is sleep truncation and/or disruption – either way, the risk of serious wrecks rises exponentially if drivers can’t lock in their “anchor sleep,” which is sleep at the same time and in the same place every day – just like nearly everyone else on the planet.

This is why drivers get so frustrated when management ask them to be productive, on-time, courteous and safe on the road, but yet never give them the opportunity to get the right amount of quality and quantity sleep to do so. Anchor sleep is vital and it’s central to any biocompatible scheduling program in which driver sleep requirements and preferences are integrated into load dispatch and routing workflows.

The Integration of Sleep Science

Most industries – including trucking – focus on regulating hours worked with the premise that a driver will be well-rested for the next period of work. The problem is that no one teaches the driver how to rest. For drivers, it’s hit or miss, since the timing of sleep can occur at anytime during the day depending on schedules and load requirements. If the industry were to regulate daily sleep requirements as proposed by the Hours of Sleep project in 2006, then not only would road safety improve, drivers would feel much better about themselves and their jobs. Essentially, we’re currently regulating the wrong thing.

Schedule Design

Getting the right balance between work and rest is the most important factor. Drivers are creatures of habit, so developing a set routine of days on and days off is not only important for personal reasons, but allows drivers to dispel accumulated sleep debt from the previous week of work. Sleep debt (the difference between what you need and what you get) accumulates rapidly, and even though you don’t need an extra hour of sleep for every hour you miss, you do need two periods of consecutive nights of sleep every seven days to reset the sleep debt to zero.

This partly explains why most long-distance truckers are so tired – because with the current hours of service rules for 34-hour restarts, they’re only getting one period of night sleep every seven days. Missing that second night of sleep means that their sleep debt slowly builds over successive weeks resulting in what’s known as “cumulative fatigue.” Because it appears gradually, drivers slowly feel worse and worse but are unable to pin the cause on anything specific. For new drivers in the industry, cumulative fatigue hits around the 90-day mark, which coincides with the spike in voluntary terminations.

Sleep Hygiene

Setting the stage for sleep has a major bearing on both the quality and quantity of the sleep. Since the primary function of sleep is to “recharge the batteries,” the brain has a clever way of shutting down all non-essential bodily functions to conserve energy. This includes temperature regulation, alertness, memory and muscle tension among a range of functions that all consume large amounts of energy during waking hours. You sleep best when the sleep environment is cool and dark; for truckers this means:

• Completely darkened sleeper berths so that light does not interfere with sleep
• Separate heating and cooling systems for sleeper cabs so drivers (and their neighbors) aren’t continually being woken by truck engines starting up repeatedly
• Clean bed linen and a mattress of high quality – memory foam is highly recommended by truckers.

Sleep Education

Drivers and fleet managers must first educate themselves in the science of sleep, thereby allowing biocompatible scheduling practices to follow. Notice we are very careful not to use fatigue education here because fatigue is a symptom of sleep deprivation and/or disruption, not the cause.

Trip Planning

For drivers there are some small changes that will have a profound impact:

• Make sure each shift starts around the same time every day. That way “anchor sleep” occurs at the same time
• When booking appointment times for loads, factor in the drivers’ preferred sleep and driving patterns
• Teach drivers to pull over when they’re not tired and trip-plan accordingly. Telling drivers to pull over when they’re tired is like saying drink water when you’re thirsty; it’s too late since you’re already dehydrated. This may sound counterintuitive, but it works.

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Data, data, data

Electronic logging devices produce a rich stream of reliable data that is incredibly valuable when measuring risk and accident probability. Most data science teams are very good at identifying the driving and rest patterns that correlate to accidents. The most successful companies are those that use compliance data to better understand driver risk profiles.

For truckers, a biocompatible schedule that includes flexibility would look as follows:

• A minimum of six hours of continuous sleep every 24 hours – at a time of the driver’s choosing
• Two periods of night sleep every seven days to dispense any accumulated sleep debt
  • A period of night sleep must span the hours of 8:00 p.m. to 8:00 a.m. (i.e., no work can occur during this period)
• Naps placed strategically throughout the day at the driver’s discretion
  • Naps replace the current 30-minute break at the 8-hour mark with timing at the driver’s discretion (i.e., when he/she is actually tired)
• Same start time every day (give or take 20 minutes)

Shippers also have a role to play since they can become a “Shipper of Choice”by providing sleep and rest facilities, allowing drivers to sleep in their trucks during the loading and unloading process, and most importantly, keeping dock time to a minimum and making sure appointment times are strictly adhered to. Drivers have a saying for shippers and fleets who ignore the driver – it’s called “hurry up and wait” where they take risks to make an appointment only to be told, “we’re not ready for you.”

By the numbers: In a 10-year study conducted by a large trucking insurer of nearly 20,000 accidents in which the number of accidents per hour were normalized by the number of trucks on the road within each hour, researchers found:

• Despite most severe accidents occurring between midday and 5:00 p.m., drivers are four times more likely to have a severe accident between midnight and 5:00 a.m.
• Drivers are three times more likely to have an accident during night time hours (6:00 p.m.  – 6:00 a.m.) compared to daytime hours (6:00 a.m. – 6:00 p.m.)
• The average accident cost is highest between the hours of 3:00 a.m. and 7:00 a.m.
• The relative risk or probability of a severe accident is highest when the human body is designed to sleep (i.e., when core body temperature drops to conserve energy between 11:00 p.m. and 7:00 a.m.)

In another published study conducted over a six-month period by a large telematics company in which 1,651 drivers attended sleep education classes (representing 44 percent of the driver population), some amazing results were produced.

Compared to sleep-educated drivers in the study group, drivers in the control group who did not attend a sleep class and were just taught hours of service compliance:

• Incurred an average accident cost 7.2 times higher
• Had twice as many loss-of-control accidents
• Experienced five times as many “run-off-road” accidents

Compared to the control group, drivers in the sleep study group:

• Had one rollover compared to 14 in the control group (the fleet’s normal rollover rate)
• Were 30 percent less likely to voluntarily terminate employment
• Were 6.75 times less likely to have a service failure (running late while under dispatch)

The productivity gains are also substantial since it’s a well-known fact that well-rested drivers run more miles. Numerous studies show drivers who are taught how to sleep during their off-duty time run about 10 percent more miles per tractor-week.

When the “Hours of Sleep” hours of service exemption application was proposed to the FMCSA in 2006, it included all of the biocompatible requirements listed above with productivity benefits including an extra hour of rolling time every 11-hour shift. This equated to an extra 50 miles per day, which would have not only made a significant impact on operating margins, it would have given drivers the equivalent of a $0.02 per mile pay raise. The FMCSA rejected the exemption application on the grounds that the entire industry was not yet on electronic logs, and until such time as that happened the agency would not reassess the situation. Maybe now is the time to apply for more flexible performance-based hours of service regulations with the ELD mandate fully implemented.

Allowing drivers the flexibility to structure work and rest around their own personal requirements –  accompanied with the appropriate sleep education – will have a profound impact on trucking in the United States as it already has in other countries.