IT MIGHT have seemed like one presentation at the National Tank Truck Carrier Safety Seminar was for the birds, but the talk of larks and owls took on a very serious meaning when related to driver fatigue.
Dean Croke of Circadian Technologies, Lexington, Massachusetts, defined the “owl drivers” as those who function best during night hours while the “larks” are at their most alert during the day. That means owls shouldn't be driving during the day, and larks should be in bed at night. At the same time, there are certain people who can fit into both categories and can work more variable hours. With those definitions in mind, it's not too hard to understand that performance suffers when a lark is trying to chirp at midnight and an owl has to hoot at noon.
Statistics indicate that 77% of accidents occur between 11 pm and 7 am, while 60% happen from 4 am until 6 am. In addition, accidents that occur from 4 am until 6 am are likely to be more serious, causing more personal injuries and resulting in greater vehicle damage. About 1-2% of revenue suffers as a result of accidents caused by fatigue.
Typically, people who work night hours don't get enough sleep during the day to make up for the sleep deprivation. Drivers who have been without sleep suffer temperature and blood pressure alterations and mood swings.
“It's how many hours drivers have been awake, not how many hours they have been driving,” Croke said, discussing the reduction in alertness as fatigue begins to take its toll.
Croke pointed out that cross-country drivers must deal with time zones changes, which also affect sleep patterns. He estimated that one hour per day is needed to adjust to each variation in time zones. As people age, their body clocks begin to change and their sleep patterns are more erratic.
To combat the costs that fatigue causes, carriers can develop programs to improve driver performance by making assignments that coincide with their sleep patterns. A review of accident records may indicate whether a driver suffered from sleep deprivation. While adjusting the driver schedule and developing a sleep deprivation program may be an added expense in the short term, long-term benefits are achieved, said Al Lacombe of Dupré Transport, Lafayette, Louisiana. Retention is improved, log violations are reduced, and relationships between company and drivers are enhanced.
Another benefit of determining who is an owl and who is a lark is that it enables drivers to understand their body clock and how it affects their performance. They learn to handle downtime so that the needed sleep can be obtained.