Driver performance due to small unmanned aerial system applications in the vicinity of roadways

Small unmanned aerial systems (sUAS), or drones, have become increasingly utilized for a myriad of applications in the vicinity of roadways and can offer a low-cost alternative to many labor-intensive data collection techniques, including infrastructure inspection, roadway marking data collection, and more. To collect much of this data with a desired degree of accuracy, sUAS must be flown near moving vehicles, pedestrians, and/or bicyclists. However, sUAS, and their operators, have the potential to be a distraction to drivers. Through a full-immersion driver simulator study and post-experiment questionnaire, this study furthered the current state-of-the-literature and investigated the potential for sUAS to be flown in the vicinity of roadways in the future as well as potential safety implications of those circumstances. Specifically, driver performance due to drone height and the presence of drone operators was evaluated. The results of the driving simulation study revealed that participants were more visually distracted in situations where the operators and drone were both present compared to the drone only scenarios. Furthermore, in 11% of all analyzed situations, drivers were critically visually-distracted as shown by a continuous glance of two seconds or more at the drone or operators. The post-experiment questionnaire revealed that approximately 30% of participants had seen a drone in flight near a roadway prior to this study. Ultimately, this research provides recommendations to policymakers for creating regulations on the use of sUAS in the vicinity of roadways.     

Individual glance strategies and their effect on the NHTSA visual manual distraction test

The purpose of this paper was to investigate how individual differences in glance strategy could impact the glance performance test defined in the NHTSA visual manual distraction guidelines. Better understanding of the test procedure could help development of new technology for safe driving. A custom in-vehicle information system was developed and assessed in a driving simulator by eighteen participants. The interfaces were designed according to recommendations in the NHTSA guidelines and contained manual radio-tuning tasks, sound settings tasks and six letter spelling tasks. Two of the six tested interfaces fully complied with the test. In addition, clear individual differences in glance strategy were found among the participants. Four individual glance strategies were identified. Two of these, long glancers and frequent glancers, highly affected the outcome of the compliance test. Participants belonging to the long glancers and the frequent glancers categories were identified as statistical outliers in many test cases. For example, if the individual values of these participants were replaced with sample mean, the number of complying interfaces would increase to five out of six, which is more in line with expectations for these interfaces. The results of this study show that individual variations in glance strategy exist. Also, these individual variations seem to have a non- negligible influence on the result when performance-testing of in-vehicle interfaces is done according to the NTHSA guidelines.     

A simulator study of factors influencing drivers’ behavior at traffic lights

Drivers’ reactions to changing traffic lights have an impact on safety at intersections. We examined the influence of transient factors – more specifically time pressure and social context, both conducive to traffic-light violation – on behavior behind the wheel when a traffic light changes. We carried out an experiment on a driving simulator. The participants were 94 car drivers (53 males) with a mean age of 21.7 years. They drove under time pressure vs. no time pressure. At several intersections the participants were alone (no other drivers present), whereas at several other intersections they were behind a line-up of vehicles, the last of which ran the yellow light (other drivers present). As expected, time pressure and social context (presence of other drivers) increased participants’ risky behaviors while approaching, and going through traffic lights, as well as undesirable rapid accelerations when the signal changes to green. The effect of time pressure on yellow-light running was not mediated by approach speed, which showed that participants in a hurry were likely to run lights intentionally. The results are interpreted in view of proposing effective measures for reducing yellow-light running and rapid accelerations at traffic lights.     

Analysis of factors affecting drivers’ choice to engage with a mobile phone while driving in Beijing

In the current work, we examined reasons that drivers choose to engage with a mobile phone while driving in Beijing. An Internet survey was administered to collect data about talking and texting while driving. Conversations were sorted into different types. Respondents were requested to indicate the frequency of initiating a call or text, perceived risk, perceived importance and emotionality of the call or text. A structural equation model of talking and texting while driving was developed with perceived risk, perceived importance and emotionality of the call as predictors and compared to a similar model with U.S. drivers. Unlike the U.S. data, perceived risk has a significant negative impact on the choice to call or text among drivers in Beijing. Results also show that perceived importance of the call is a major factor affecting the usage of phone while driving. Even though drivers know it is dangerous and illegal, Beijing drivers choose to talk on mobile phones while driving, but they prefer not to text.     

The effect of fatigue driving on car following behavior

Existing fatigued driving analysis methods mainly focus on lateral driving performance by using the measurements related to the steering wheel or lane position. There is a lack of research on longitudinal car following behavior. In this study, 40 professional drivers are invited to participate in field expressway driving experiment, lasting at least for 6 h. During the test, their performance is measured in terms of their self-reported fatigued driving level according to the Karolinska Sleepiness Scale (KSS), the PERcentage of eye CLOSures (PERCLOS) and the Time Headway (THW). Then the effects of the fatigued driving level on car following behavior are evaluated. The results indicate that the fatigue level (for both KSS and PERCLOS) has significantly impact on THW parameters, including the mean, standard deviation and minimum THW. An increase in KSS and PERCLOS leads to a lower mean and minimum THW. Meanwhile, the standard deviation of THW increases with the increase of KSS and PERCLOS. In conclusion, this study found that a higher fatigue level leads to the driver keeping a smaller THW when following another vehicle and choosing shorter THW to make lane change. More deviation of car following performance was also found with the increase of fatigue level. Therefore, the findings of this study can be used to explain fatigue as one of the major reasons for rear-end collisions. Also, the research findings demonstrate the impact of fatigue on driving behavior in terms of car following performance, which can be used as a measurement for monitoring fatigued drivers.     

The impact of safety climate on safety related driving behaviors

This study explored the impact of safety climate, age and tenure as a driver on safety related driving behaviors among 290 company drivers in Ghana. The study found a negative relationship between safety climate and studied work-related behaviors: speeding, rule violation, inattention and driving whiles tired. The study also found that age significantly predicted the extent to which drivers engaged in safety related driving behaviors. The results showed that young drivers (aged 20–35 years) engage more in risky driving behaviors relative to adult drivers (aged 36–60 years). The study also found that the tenure of a driver did not significantly affect work-related driver behaviors. The findings from this study suggests that in the quest to reduce safety related traffic accidents and its resulting consequences such as injuries, absenteeism and deaths, a critical organizational variable that organizations can use to mitigate this canker is commitment to and strict adherence to safety practices and regulations. By extension, the findings suggest, Ghana’s commitment to safety practices and enforcement of safety regulations and policies among others can help the country win the battle against road accidents.     

Mobile phone use while driving-literary review

This paper analysis published results of the research into the connection between mobile phone use while driving and traffic safety. Ever since the introduction of the first mobile phones, the authors have been examining the risks associated with its use in traffic, namely: prevalence or frequency of mobile phone use while driving, characteristics of drivers who make more frequent use of mobile phones, the connection between mobile phone use while driving and a car crash risk, a link between mobile phone use while driving and perception of risk, effects on driving performance of using various modes of mobile phones while driving (“hands-free” or “hand-held”), psychological factors influencing driver's decision to use a mobile phone while driving, etc.It is important to point out that the results of some studies indicate that using a hands-free mobile phone while driving does not provide greater safety as compared to the use of hand-held mobile phones while driving. Generally speaking, younger male drivers tend to use mobile phones more often while driving than women and older males.This paper analyses the results of studies which were published in 60 papers from 1994 to 2013.The analysis of the papers selected for research confirms detrimental effects of mobile phone use while driving. Also, four phases in the process of understanding the issue of mobile phone use impacts while driving have been established or identified. The first phase gives the analysis of the prevalence or frequency of mobile phone use while driving. The second phase identifies the characteristics of drivers who tend to use mobile phones more frequently while driving. The third phase concerns research into impacts of using different modes of mobile phones while driving on driving performance (“hands-free” or “hand-held”). Finally, the fourth phase deals with research into risks of mobile phone use while driving (“hands-free” or “hand-held”). The importance of this paper is reflected in that it can help traffic safety policy makers, on the basis of better understanding of the issue of mobile phone use impact while driving, to develop effective strategies aimed at reducing the extent of mobile phone use while driving.     

Are situation awareness and decision-making in driving totally conscious processes? Results of a hazard prediction task

Detecting danger in the driving environment is an indispensable task to guarantee safety which depends on the driver’s ability to predict upcoming hazards. But does correct prediction lead to an appropriate response? This study advances hazard perception research by investigating the link between successful prediction and response selection. Three groups of drivers (learners, novices and experienced drivers) were recruited, with novice and experienced drivers further split into offender and non-offender groups. Specifically, this works aims to develop an improved Spanish Hazard Prediction Test and to explore the differences in Situation Awareness, (SA: perception, comprehension and prediction) and Decision-Making (DM) among learners, younger inexperienced and experienced drivers and between driving offenders and non-offenders. The contribution of the current work is not only theoretical; the Hazard Prediction Test is also a valid way to test Hazard Perception. The test, as well as being useful as part of the test for a driving license, could also serve a purpose in the renewal of licenses after a ban or as a way of training drivers. A sample of 121 participants watched a series of driving video clips that ended with a sudden occlusion prior to a hazard. They then answered questions to assess their SA (“What is the hazard?” “Where is it located?” “What happens next?”) and DM (“What would you do in this situation?”). This alternative to the Hazard Perception Test demonstrates a satisfactory internal consistency (Alpha = 0.750), with eleven videos achieving discrimination indices above 0.30. Learners performed significantly worse than experienced drivers when required to identify and locate the hazard. Interestingly, drivers were more accurate in answering the DM question than questions regarding SA, suggesting that drivers can choose an appropriate response manoeuvre without a totally conscious knowledge of the exact hazard.     

Driver brake vs. steer response to sudden forward collision scenario in manual and automated driving modes

In autonomous vehicle operation, situations may arise when the driver is required to re-engage in manual control of the vehicle. Whether the control handoff from vehicle to human is done in a structured or unstructured manner, the process may be affected by the driver’s state, i.e. distracted or not. The study reported here was designed to measure a non-distracted driver’s response to a sudden forward collision (FC) event, in which the driver would assume manual control of the autonomous vehicle. Three driving scenarios were investigated: autonomous vehicle driven with full collision avoidance support, autonomous vehicle driven without collision avoidance support, and vehicle driven in manual mode.Forty-eight volunteers participated in a simulator study conducted in VIRTTEX. It was found that, at handoff, (1) drivers in manual mode tended to use evasive steering, rather than braking, compared to drivers in both the autonomous modes, (2) between subjects variations in speed were higher for the automation with collision support condition than for the other two scenarios, (3) for both autonomous driving scenarios, drivers reaction times were longer than for manual driving. In some cases the driver response was so late and the distance remaining so reduced that crash avoidance might be unfeasible. At a minimum, results of this study suggest that drivers may benefit from appropriate driver assistance technologies when a crash imminent situation is suddenly encountered.