Detailed research on the truck crashes revealed that these happened because low-frequency vibrations of the truck make drivers feel sleepy or tired. However, those drivers were only tired, not fatigued in an hour of driving.
According to an Australian researcher Stephen Robinson, the low-frequency vibrations ranging between 4-7 Hz come on the car floor and seat of the drivers, causing them to feel extremely drowsy. Those drivers tend to calm down in the state of ‘inattentiveness’ or ‘zoning-out.’
A team of 15 volunteers reviewed that the truck drivers while driving become drowsy, and at the higher risk of crashing for at least 15 to 30 minutes although the drivers were not deprived of sleep and did their regular tasks on the next day.
The conclusion of all this was that this sort of vibration-induced drowsiness could be noticed after 15-30 minutes of exposure.
The test comprised of driving trainer, steering wheel, and a monitor displaying a road in front of him. This whole gear attached to the large steel plate, which was set in a way to reduce the amplitude and frequency of the vibrations practiced in the real car on the actual road.
The observers were to detect visually when the subjects start being drowsy by deterioration in their lane-tracking aptitude. The observers also used an eye-tracking device to identify the relaxing eyelids. And there was a strong relationship between the relaxing eyelids and false lane tracking.
The overall result of this is that driving a motor vehicle, either it is a heavy truck or a smaller one requires attention and constant mental workload as vibrations are linked closely to drowsiness. Therefore, the sleepiness and failed attention quickly compromise the awareness needed in the current situation.
Implications for Trucking
There is a massive difference between being ‘tired’ and fatigued, especially when it comes to a truck crash. Fatigued implies that there must be an hours-of-service agreement problem. How can a driver be so tired to sleep at the wheel? If the driver has taken their resting hours.
Regrettably, this fatigue-related crash fits comfortably with the ELD/HOS narrative, which the safety advocates use consistently. Although these lulls in attention, while driving on a straight peaceful path, along with a constant roar of the engine are inevitable. Everyone might have experienced it. And most of them also have tried avoiding this by taking some preventive measures, including opening the window or turning up the radio.
But, what about the suggestion of Professor Robinson? That there exists a link between the frequency of truck vibrations and the rhythm of some brain waves. According to him, it is the truck that is responsible for making us sleep.
If these low-frequency variations are responsible for drowsiness, then what will happen when you route trucks down so close that the drivers have a little stimulation to keep them alert? These truck engineers are aware of these low-frequency vibration implications.
There is a dire need to address this issue. We need to make the rough and tumble trucks instead of cloud-like to drive so that this will keep us awake.