This is now my eleventh article for NBT dealing with fatigue. But unlike many others, it is not theoretical. Nor is it complex. Most importantly, it involves an idea that is not hard to implement even in a heavily-Unionized operating environment. This is because bio-sensitive driver assignment would result in drivers being assigned to shifts that they would likely prefer in the first place.
Bio-sensitive driver assignment is really a close cousin of progressive driver assignment (see October, 2011 issue of National Bus Trader). But it need not be. Progressive driver assignment effectively turns seniority on its head, and it is not hard to envision the institutional resistance to such an approach. But bio-sensitive driver assignment simply matches drivers’ shifts to those hours when drivers would likely be most alert. This is hardly controversial or confrontational since, again, the vast majority of drivers would prefer to drive when they were most alert.
Tales from the Paratransit World
During the 10 years I spent, long ago, directing my own 70-vehicle paratransit system, we had the luxury of an enormous variety of shifts – some split shifts, some single shifts as long as 10 hours or so where lunches were taken usually when the scheduled vehicle had a cancellation or a “no-show.” (Otherwise, we would “cover” a trip or two with another vehicle to give the otherwise busy driver a meal break and/or rest breaks.) With this variety of shifts, I could accommodate almost every driver’s preference for shift times, particularly start times. This was extremely important in my Los Angeles-based operation, since many of our drivers were musicians driving as their “day gigs.” The last thing I wanted to do was put some rock guitarist on the road in the early morning hours. Instead, such individuals were already assigned to long single shifts that began close to noon.
At the hiring level, we asked our driver-candidates only two simple questions – but those two questions helped us determine not only if the drivers were morning people (or “larks”) versus night people (“owls”), but whether or not they had a conventional, 24-hour sleep-wakefulness cycle, or one significantly longer or shorter. These two questions were as follows:
- You’re on vacation for two weeks at a place where you can do anything you want at any hour of the day, and thus, there is no reason to go to sleep at any time, or to awaken at any time. So, let’s say you went to sleep at midnight on your first night: At what time would you awaken naturally, and completely rested, the next morning?
- OK. Now that you had awakened at that time, fully rested, at what time would you go to sleep the following night?
The difference between the two answers I got told me almost everything I needed to know:
- If the applicant’s second night of retirement was later than midnight, he/she had a long sleep-wakefulness cycle.
- If the applicant’s second night of retirement was earlier than midnight, he/she had a short sleep-wakefulness cycle.
- If the two times were the same, I could assign that driver to almost any shift or combination of split-shifts.
Adjusting to One’s Sleep-Wakefulness Cycles
Before the invention of the electric light bulb (for most of us who were not rich enough to burn torches all night long) and the artificial timepiece, individuals with sleep-wakefulness cycles that differed much from one rotation of the Earth on its axis usually did not survive very long – unless he or she had a parent, sibling or friend to roust him or her out of bed the minute the sun came up. This is because someone walking around at night would likely fall into a pit. Similarly, someone sleeping much beyond sunrise would likely be devoured by a carnivorous, “day-active” animal. Things were pretty tough back in those days, but these dynamics tended to eliminate the night owls and late sleepers pretty efficiently. Of course, in Today’s world of artificial light and timepieces, much less our easy isolation from carnivorous animals, these dynamics no longer weed out the night-owls or late-sleepers. So in assigning drivers to shifts, we are stuck with both types, and the intuitively-obvious problems that come with them.
Of course, in the tough, dangerous blue-collar world of even a few hundred years ago, daily life was pretty exhausting, and falling asleep not terribly difficult. Further, as a principle of science, when people are exposed to bright sunlight, their sleep-wakefulness cycles tend to be much closer to a single rotation of the Earth on its axis than someone working mostly under artificial light (which tends to extend one’s natural sleep cycle on the average of an hour or so longer). So now, those with longer- or shorter-than-24-hour sleep-wakefulness cycles must cope with their characteristics in order to live comfortably on a 24-hour day that our sunlight/darkness pattern and the social and work environment it dictates require us to do.
Those with shorter cycles (far more common than those with longer ones) have few adjustments to make. The best by far is simply taking a single, moderate-length nap. (If one naps for two long, this nap typically impedes one’s ability to get to sleep on schedule that night.) If that is not possible, or not sufficient, all that person needs is a jolt or two of caffeine. These adjustments are so commonplace that practically no one even thinks of them as the adjustments to the 24-hour society that they genuinely are. Regardless, these adjustments are easy, and such individuals pose little risk to alertness – unless, of course, one has no access to caffeine, and more importantly, no opportunity to take a brief nap at the period when one most needs it.
Individuals with a longer sleep-wakefulness cycles have more challenging problems. At the “edge” of this subclass exist individuals who simply stay up late, and are forced to wake up a bit groggy to the sound of an alarm clock (or perhaps their spouse shaking them a few times). Further, as tired as they may be, such individuals can rarely nap. And a swig of even decaffeinated coffee, or a bottle of soda, can cause them to fall asleep hours later than the normal time even for them.
The problem is, one’s sleep-wakefulness cycles cannot be naturally modified. The key word in that sentence is “naturally.” Instead, as one grows into adulthood, and over the decades builds up a tolerance to initially mild sleep medications, one is forced to imbibe an increasingly-strong “cocktail” of sleep medications. Therefore, management must be careful to assign those drivers with longer sleep-wakefulness cycles to later-starting shifts – when they are most alert and least likely to fall asleep at the wheel. Interestingly, such individuals are invaluable to the motorcoach industry because they can reliably be assigned to late-night or even “owl-period” shifts will must less risk of them falling asleep at the wheel. The misunderstanding about these dynamics, combined with the failure to respect them, accounts for many of the catastrophic accidents that occur during the “owl” period (i.e., between 2 and 6 AM). In contrast, the assignment of “nocturnal” drivers to early morning shifts accounts for the large number of catastrophic accidents that occur during the mid-morning hours.
Priorities for Shift Preferences
As much of a challenge as these variations suggest driver assignment might be, it is surprisingly not challenging at all – particularly with a dollop of union flexibility and some common sense at the driver-assignment level, presumably when management is armed with the information noted above. This is because, again, most drivers would prefer to drive when they are alert. Among the most typical reasons a driver would likely select his or her shift are:
- The time the shift begins (both with respect to optimizing sleep and rest, compromised to a degree by the constraints of family or social life).
- Whether the shift is a long, single one or a “split-shift.”
- Whether the shift occurs during normal waking hours (opposed to the “night” or “owl” periods (roughly 7 PM to midnight, and midnight to 5 AM, respectively)
- The amount of layover or recovery time on the route
Other factors, like transporting fewer wheelchair users, better things to do during a long layover, or avoiding “bad neighborhoods” fall under consideration. But not nearly as heavily as the first four noted above.
The point is, since most passenger transportation operations (schoolbus services excepted) involve a range of shifts, drivers can usually select those they would prefer in the first place. Factors like seniority interfere with the optimization of this principal to a degree: For example, some drivers may be willing to sacrifice a degree of driving when fatigued in order to spend more time with their families. But by asking the proper questions of one’s driver pool, and bucking seniority in one important place where doing so really matters, management should be able to find a shift both desirable and safe for all or most of its drivers.
Employing these principles is the most difficult for small operations with few shift options and small driver pools — the most common example and most at risk being small charter operations. It is not for no reason that the vast majority of catastrophic motorcoach accidents involve small companies with few choices, and as such, companies that realistically cannot afford to turn down any, or at last most, trip requests. Part 2 of this installment will explore some creative approaches to resolving this problem – approaches commonly employed by both large and small companies often working together to address their respective fluctuations in supply and demand.