On average, these drivers had been awake only five hours at the time of the crash. In general, it was observed that drivers can develop fatigue while on the job, but they can also bring fatigue with them to the workplace. The two different modes of fatigue are equally hazardous, but they must be dealt with in different ways. We presented our findings at the Annual Meeting of the Human Factors and Ergonomics Society. Under conditions of limited visibility, drivers may be uncertain about whether distant images are actually oncoming vehicles.
Warning systems provide information intended to help drivers decide whether to pass another vehicle.
The results of this study are expected to be useful to designers of in-vehicle warning systems. In the Truck Simulator Laboratory, we simulated a passing situation on a two-lane rural road, and compared performance using two warning thresholds. The conservative warning threshold detects virtually all unsafe passing situations, but also causes occasional false alarms, incorrectly concluding that some safe situations are unsafe. The less-conservative warning threshold provides more accurate information about safe passing situations, but occasionally fails to warn of an unsafe situation. Preliminary results indicate that warning systems improve performance over no warning system, and that the less-conservative threshold improves performance over the conservative threshold.