It has always amazed FleetWatch just how much detailed research work goes into the various developmental aspects of trucks. This article from Daimler Trucks in Stuttgart caught my attention in that it shows an aspect of research aimed at improving the lot of truck drivers that one would never have imagined would be embarked on.
It all revolves around the question: Does the biological effect of light have a positive influence on the well-being and performance of truck drivers? A research team from Daimler has been exploring this interesting question in the darkness of Finland’s polar night.
A total of eight Daimler test drivers simulated two typical working weeks for truckers at the site in Rovaniemi. The truckers alternated between driving for one week in a truck cab with conventional lighting and for another week in a cab with a Daylight+ module that provides additional daylight while driving and during breaks.
The idea for Daylight+ arose during the course of a series of experiments at the sleep lab at the University of Regensburg. Daimler researcher Siegfried Rothe is involved in numerous projects to help improve working and living conditions for truck drivers and therefore to improve the image of this occupation.
He subsequently determined that, due primarily to the outline shape of a conventional truck cab, only a comparatively low percentage of natural daylight reaches the driver’s light receptors. This finding prompted Rothe to think about potential solutions.
The results of an initial series of experiments with engineers from the test drive department were unambiguous. The subjective condition of all test subjects improved significantly under the influence of an additional dose of light, regardless of the time of day. Another finding proved surprising: the test drivers with more daylight in the cab drove more economically.
During the experiments in Rovaniemi, the test subjects were only ever compared against themselves. That is, the experiments examined how a driver’s performance changes when they are exposed to additional biologically effective daylight under clearly defined conditions. The extra dose took three forms involving different intensities:
- Steady light while driving, whereby the intensity was adjusted to the exterior light level.
- An intense light shower of maximum intensity during the tests before and after driving.
- Light while reclined, likewise of maximum intensity, during breaks while the driver relaxes in their seat, which has been positioned for a power nap.
During the night, the test subjects slept in a normally darkened truck. For the test drivers, these experiments in the Arctic Circle were a tough test of their capabilities. The team documented the test results with support from co-researcher Dr Michael Schrauf and the use of electroencephalography (EEG), electrocardiography (ECG) and electrooculography (EOG) and other physiological measurements, as well as saliva samples (to ascertain levels of the sleep hormone melatonin).
Mental state and professional performance, which are closely related, were examined using standardised psychological test procedures (sustained attention and reaction tests on the computer) and by recording vehicle data through the FleetBoard telematics system.
At the end of the two-week cycles, the individual drivers were interviewed, having previously recorded their subjective impressions. Richard Schneider and Philippe Strasser, two truck test drivers for Daimler, spent time in the Arctic Circle at the darkest time of the year, just before the winter solstice. Both of them expressed enthusiasm for Daylight+ separately.
Feedback from the truck test drivers also provided a new insight for Siegfried Rothe. The drivers consistently reported that they perceived the space inside the cab to be considerably more pleasant with the additional light fitting.
“When designing the series of tests, we hadn’t even considered that the space might appear larger,” admitted the head of the experiment.
Rothe estimates that it will take several months to sift and analyse the extensive data from the series of experiments conducted in the Arctic Circle. “Only then we will be able to make a recommendation as to whether the test findings should advisably lead to changes in the design of cab lighting.”
Amazing stuff isn’t it?