BENEFITS AND COST OF DUAL-TASKING IN A VIGILANCE TASK: A LABORATORY AND DRIVING SIMULATOR INVESTIGATION

It is believed that under certain conditions, the presence of a secondary task such as a cell phone conversation would minimize a decrease in vigilance. The current study investigates this assumption by using two different vigilance paradigms. Further investigations were done by applying the same secondary task conditions to a monotonous driving scenario in a simulator. Results from the vigilance studies showed robust effects of dual task interference, and improvement in task performance for participants engaged in dual task from beginning to end. It was noted that the benefit of an improvement in task performance did not outweigh its cost as the reported improvement only reached a level similar to that of an individual who was low in vigilance. Results from the driving simulator indicated a possible driving improvement with the presence of a secondary task during later stages of the driving task as indicated by smaller lane keeping variability. The perceived improvement was questioned as there was a significantly poorer recall memory under dual task conditions. In general, it might be suggested that a secondary task may improve task performance under vigilance conditions, but the reported benefit may not outweigh its costs

Potential Benefits and Costs of Concurrent Task Engagement to Maintain Vigilance: A Driving Simulator Investigation

Permissions were not obtained for sharing the full text of this article.Objective: The objective of this study was to investigate the nature of concurrent task interference during a vigilance task and to determine whether a concurrent task improves performance with decreased vigilance. Background: Research has repeatedly shown that engaging in a cell phone conversation while driving increases the risk of getting into crashes. At the same time, it has also been found that task monotony could lead to an increase in crash risk. There is evidence that suggests that engaging in a concurrent task reduces the effects of monotony, leading to an improvement in vigilance task performance. Method: A monotonous drive in a driving simulator was used to investigate the effects of a concurrent verbal task. Three task conditions were used: no verbal task, continuous verbal task, and late verbal task. Results: When engaged in a secondary verbal task, drivers showed improved lane-keeping performance and steering control when vigilance was lowest. Conclusion: A strategically placed concurrent task can improve performance when vigilance is at its lowest. Application: There is potential for the design of a countermeasure system that can be strategically activated by an automated system monitoring driver performance

A Strategically Timed Verbal Task Improves Performance and Neurophysiological Alertness During Fatiguing Drives

This is the author's accepted manuscript. The original publication is available at http://hfs.sagepub.com/content/56/3/453.Objective: The objective of this study was to investigate if a verbal task can improve alertness and if performance changes are associated with changes in alertness as measured by EEG. Background: Previous research has shown that a secondary task can improve performance on a short, monotonous drive. The current work extends this by examining longer, fatiguing drives. The study also uses EEG to confirm that improved driving performance is concurrent with improved driver alertness. Method: A 90-min, monotonous simulator drive was used to place drivers in a fatigued state. Four secondary tasks were used: no verbal task, continuous verbal task, late verbal task, and a passive radio task. Results: When engaged in a secondary verbal task at the end of the drive, drivers showed improved lane-keeping performance and had improvements in neurophysiological measures of alertness. Conclusion: A strategically timed concurrent task can improve performance even for fatiguing drives. Application: Secondary-task countermeasures may prove useful for enhancing driving performance across a range of driving conditions

Improving Highway Work Zone Safety

Highway work zones disrupt normal traffic flow and can create severe safety problems. Due to the rising needs in highway maintenance and construction in the United States, the number of work zones is increasing nationwide. With a total of 1,010 fatalities and more than 40,000 injuries occurring in 2006, improvements in work zone safety are necessary. The three primary objectives of this research project included: 1) to determine the effectiveness of a Portable Changeable Message Sign (PCMS) in reducing vehicle speeds on two-lane, rural highway work zones; 2) to determine the effectiveness of a Temporary Traffic Sign (TTS), (W20-1, “Road Work Ahead”); and 3) to determine motorists’ responses to the signage. To accomplish these objectives, field experiments were conducted at US-36 and US-73 in Seneca and Hiawatha, Kansas, respectively. During the field experiments, an evaluation of the effectiveness of the PCMS was conducted under three different conditions: 1) PCMS on; 2) PCMS off, but still visible; and 3) PCMS removed from the road and out of sight. The researchers also divided the vehicles into three classes (passenger car, truck, and semitrailer) and compared the mean speed change of these classes based on three different sign setups: PCMS on, PCMS off, and the use of the TTS (W20-1, “Road Work Ahead”). A survey was also conducted at the experimental work zones to obtain a general understanding of the motorists’ attitudes as they traveled through the construction areas. Based on the data analysis results, researchers concluded that the presence of the PCMS effectively reduced vehicle speeds on two-lane highway work zones. A slow speed is more likely to reduce the probability of a crash or the severity of a crash. In addition, researchers performed a univariate analysis of the variance test to determine if a significant interaction existed between motorists’ responses and the sign conditions. The results showed a significant interaction between the signs and passenger car vehicles