Traffic flow harmonization in expressway merging

Steering a vehicle is a task increasingly challenging the driver in terms of mental resources. Reasons for this include the increasing volume of road traffic and a rising quantity of road signs, traffic lights, and other distractions at the roadside (such as billboards), to name a few. The application of Advanced Driver Assistance Systems, in particular if taking advantage of Ambient Intelligence (AmI) technology, can help to increase the perceptivity of a driver, leading as a direct consequence to more relaxed mental stress of the same. One situation where we see potential in the application of such a system are merging areas on the expressway where two or more varying traffic streams converge into a single one. In order to reduce cognitive liabilities (in this work expressed as panic or anger), drivers are exposed to while merging, we have developed two behavioral rules. The first (“increased range of perception”) enables drivers to change early upstream into a spare lane, allowing the merging traffic to join into mainline traffic at reduced conflicts, the second (“inter-car distance management” in the broader area of merging) provide drivers with recommendations of when and how to change lanes at the best. From a technical point of view, the “VibraSeat” a in-house developed car seat with integrated tactile actuators, is used for delivering information about perception range and inter-car distances to the driver in a way that does not stress his/her mental capabilities. To figure out possible improvements in its application in real traffic and at a meaningful scale, cellular automaton–based simulation of a specific section of Madrid expressway M30 was performed. Results from the data-driven simulation experiments on the true to scale model indicate that AmI technology has the potential to increase road throughput or average driving speed and furthermore to decrease the panic of drivers while merging into an upper (the main) lane.     

The impact of distraction mitigation strategies on driving performance

OBJECTIVES: An experiment was conducted to assess the effects of distraction mitigation strategies on drivers' performance and productivity while engaged in an in-vehicle information system task. BACKGROUND: Previous studies show that in-vehicle tasks undermine driver safety and there is a need to mitigate driver distraction. METHOD: An advising strategy that alerts drivers to potential dangers and a locking strategy that prevents the driver from continuing the distracting task were presented to 16 middle-aged and 12 older drivers in a driving simulator in two modes (auditory, visual) and two road conditions (curves, braking events). RESULTS: Distraction was a problem for both age groups. Visual distractions were more detrimental than auditory ones for curve negotiation, as depicted by more erratic steering, F (6, 155) = 26.76, p < .05. Drivers did brake more abruptly under auditory distractions, but this effect was mitigated by both the advising, t (155) = 8.37, p < .05, and locking strategies, t (155) = 8.49, p < .05. The locking strategy also resulted in longer minimum time to collision for middle-aged drivers engaged in visual distractions, F (6, 138) = 2.43, p < .05. CONCLUSIONS: Adaptive interfaces can reduce abrupt braking on curve entries resulting from auditory distractions and can also improve the braking response for distracted drivers. APPLICATION: These strategies can be incorporated into existing in-vehicle systems, thus mitigating the effects of distraction and improving driver performance.     

Driver's distracted behavior: The contribution of compensatory beliefs increases with higher perceived risk

Engaging in distractive behaviors while driving is common worldwide, despite its proven negative impact on driving safety. The current study aimed to investigate the ability of drivers' compensatory beliefs regarding distracted driving (i.e., the belief that the negative effects of an unsafe behavior can be “neutralized” by engaging in another safe behavior; e.g., “slowing down can compensate for the impact of driving distractions”) and drivers' risk perceptions to predict drivers' distracting behaviors. This study analyzed the self-reports of 304 non-professional drivers (186 males and 118 females) between the ages of 19 and 66 years. The revised questionnaires were proven reliable and valid for measuring drivers' compensatory beliefs regarding distractions, their distractive behaviors, and their perceived risk. Additionally, three components (i.e., mobile phone use, in-vehicle interactions, and mind wandering) were identified in the current study using factor analyses. The analysis of the relationships among the study variables showed that the drivers' compensatory beliefs regarding distractive behaviors were a core predictor of the drivers’ engagement in distracting behaviors, especially for behaviors with a higher perceived risk rating (e.g., mobile phone use).     

Medications and the safety of the older driver: is there a basis for concern?

Medications with central nervous system (CNS) effects, including benzodiazepines, cyclic antidepressants, antihistamines, narcotic analgesics, and hypoglycemics, have been thought to have the potential to impair driving. These drugs impair performance in younger drivers and some have been linked to an increased risk of motor vehicle crashes. Even though persons 65 years of age and older frequently take these drugs and are more susceptible to CNS effects, no direct data exist regarding whether or not medications adversely affect driving safety in this population. Thus there is an urgent need for further research in this area.     

Highly Automated Driving Impact on Drivers’ Gaze Behaviors during a Car-Following Task

ABSTRACT

The ever-increasing degree of automation in vehicles, with drivers delegating part of the manual driving task to automation, sets new research questions in terms of human–machine cooperation. Manual steering requires drivers to gaze at a distant road sections to ensure that the vehicle follows the road curvature and at a near road sections to maintain the vehicle within the lane limits. In this experiment, gaze behaviors engaged under highly automated driving (HAD) and manual driving conditions were compared. The results show a critical decrease of the number of gazes at the near road sections for the HAD condition compared to the manual driving condition. Two human-based highly automated “driving styles” were also compared, but did not translate into significant gaze behaviors modifications. Finally, no after-effect of the HAD was found on subsequent manual driving.     

The effects of using a portable music player on simulated driving performance and task-sharing strategies

This study examined the effects of performing scrollable music selection tasks using a portable music player (iPod Touch™) on simulated driving performance and task-sharing strategies, as evidenced through eye glance behaviour and secondary task performance. A total of 37 drivers (18–48 yrs) completed the PC-based MUARC Driver Distraction Test (DDT) while performing music selection tasks on an iPod Touch. Drivers’ eye glance behaviour was examined using faceLAB eye tracking equipment. Results revealed that performing music search tasks while driving increased the amount of time that drivers spent with their eyes off the roadway and decreased their ability to maintain a constant lane position and time headway from a lead vehicle. There was also evidence, however, that drivers attempted to regulate their behaviour when distracted by decreasing their speed and taking a large number of short glances towards the device. Overall, results suggest that performing music search tasks while driving is problematic and steps to prohibit this activity should be taken.     

Good intentions: drivers’ decisions to engage with technology on the road and in a driving simulator

Distraction-related accidents are, more often than not, due to the drivers’ voluntarily engagement with a secondary task. Therefore, the strategic management of in-vehicle tasks and the drivers’ decision to engage with them is an important aspect of the driver distraction phenomenon that needs to be addressed. While the consequences of distracting tasks are often assessed in settings where the risk of engaging is reduced (i.e., simulators), the drivers’ decision to engage with secondary tasks is often ignored. This study assessed the drivers’ decision to engage with secondary tasks using verbal protocols to provide insights into the drivers’ intention within a naturalistic driving setting, on the road, and in a simulated driving environment. This enabled an understanding of when drivers engage with technological distractions, why they choose to do so, as well as how they may go about doing it. Different road types were found to differentially impact the drivers’ intention to engage, as did the types of secondary tasks, with some tasks having an increased willingness to engage compared to others. Factors that increase and/or reduce the likelihood of engaging are presented. The decisions that drivers made to engage with secondary tasks in the simulator were found to correlate strongly to their decision to so on the road. This provides support for the use of simulators when assessing the drivers’ decision to engage with secondary tasks. The effect of verbal protocols on the drivers’ speed metrics was assessed to determine how they may have affected their driving performance.     

Perceptual processes used by drivers during overtaking in a driving simulator

This study investigated the control strategies and decision making of drivers who were executing overtaking maneuvers in a fixed-base driving simulator. It was found that drivers were frequently inaccurate in deciding whether it was safe to overtake in front of an oncoming vehicle. One source of error in this situation was the control strategy adopted by the driver; in several instances our drivers initiated an overtaking maneuver when the oncoming car's distance was above a critical value, even though there was not sufficient time to complete a safe maneuver. Adaptation to closing speed (produced by driving on a straight open road) also had large effects on overtaking behavior. For all participants, closing speed adaptation resulted in decisions that were delayed, of higher risk, and more variable. Actual or potential applications of this research include improved training for younger drivers and the development of in-car interfaces that reduce closing speed adaptation.     

Using eye movements to evaluate effects of driver age on risk perception in a driving simulator

Novice drivers (16-year-olds with < or = 6 months' driving experience) have the highest crash involvement rates per 100 million vehicle miles (161 million vehicle km). In the past, this was attributed to greater risk taking or poorly developed psychomotor skills. More recently, however, their high crash involvement rate has been hypothesized to be attributable largely to their relative inability to acquire and assess information in inherently risky situations. The current study seeks to evaluate this hypothesis by recording eye movements while 72 participants (24 novice drivers, 24 younger drivers, and 24 older drivers) drove through 16 risky scenarios in an advanced driving simulator. There were significant age-related differences in driver scanning behavior, consistent with the hypothesis that novice drivers' scanning patterns reflect their failure to acquire information about potential risks and their consequent failure to deal with these risks. Actual or potential applications of this research include modification of these scenarios for display on a PC as a basis for a training module that would enable novice drivers to recognize risky scenarios before they encounter them on the road, in the hope of reducing their high fatality rate.     

A comparison of the cell phone driver and the drunk driver

OBJECTIVE: The objective of this research was to determine the relative impairment associated with conversing on a cellular telephone while driving. BACKGROUND: Epidemiological evidence suggests that the relative risk of being in a traffic accident while using a cell phone is similar to the hazard associated with driving with a blood alcohol level at the legal limit. The purpose of this research was to provide a direct comparison of the driving performance of a cell phone driver and a drunk driver in a controlled laboratory setting. METHOD: We used a high-fidelity driving simulator to compare the performance of cell phone drivers with drivers who were intoxicated from ethanol (i.e., blood alcohol concentration at 0.08% weight/volume). RESULTS: When drivers were conversing on either a handheld or hands-free cell phone, their braking reactions were delayed and they were involved in more traffic accidents than when they were not conversing on a cell phone. By contrast, when drivers were intoxicated from ethanol they exhibited a more aggressive driving style, following closer to the vehicle immediately in front of them and applying more force while braking. CONCLUSION: When driving conditions and time on task were controlled for, the impairments associated with using a cell phone while driving can be as profound as those associated with driving while drunk. APPLICATION: This research may help to provide guidance for regulation addressing driver distraction caused by cell phone conversations.     

Examining cognitive interference and adaptive safety behaviours in tactical vehicle control

Concurrent mental workload degrades some aspects of driving performance, but drivers might be able to modify their behaviour adaptively to accommodate cognitive impairments. For example, they might maintain longer vehicle headway in dual-task conditions to compensate for slowed response times. Studies documenting such adaptive behaviours typically use steady-state driving scenarios such as car following. Yet, driving often involves tactical control situations in which drivers need to monitor multiple aspects of their traffic environment and to accommodate changing goals. In two simulator experiments, this study examined the impact of mental workload on safety margins (distances) that drivers keep when engaged in a tactical control task: passing other vehicles. Although drivers did increase their headway adaptively when engaged in steady-state car following (experiment 2), they did not adapt their behaviour to accommodate cognitive load when performing tactical control manoeuvres. Implications of this difference between steady-state and tactical control driving contexts, both for driving research and for driving safety, are discussed.     

Attention and driving skills in aging and Alzheimer's disease.

The number of older drivers with dementia is rising with the aging of the adult population. A public health issue is growing because of concerns about the motor vehicle accident risk posed by drivers with dementia of the Alzheimer's type (DAT) and other progressive, degenerative dementias. However, little is known about the specific perceptual/cognitive deficits contributing to impaired driving in DAT. The present paper proposes, on both theoretical and empirical grounds, that attentional skills in relation to driving should be examined in older adults with and without DAT. Such investigations should focus on normal older adults and those in the mild, early stages of dementia because the latter are the most likely among the dementia population to be still driving. Evidence is presented indicating (1) that motor vehicle accident rates are related to performance on information-processing measures of different components of attention; (2) that this relationship is greatest for measures of the switching of selective attention and less for that of divided and sustained attention (vigilance); and (3) that many of these same attentional functions, and particularly the switching of visual selective attention, are impaired in the early stages of DAT and thus may contribute to increased accident risk. Further studies of cognitive and driving performance in older drivers are necessary to establish that the attentional impairments found in mild DAT contribute to increased accident risk. Implications of these findings for driver assessment, education, and training are discussed.     

Distraction 'on the buses': a novel framework of ergonomics methods for identifying sources and effects of bus driver distraction

Driver distraction represents a significant problem in the public transport sector. Various methods exist for investigating distraction; however, the majority are difficult to apply within the context of naturalistic bus driving. This article investigates the nature of bus driver distraction at a major Australian public transport company, including the sources of distraction present, and their effects on driver performance, through the application of a novel framework of ergonomics methods. The framework represents a novel approach for assessing distraction in a real world context. The findings suggest that there are a number of sources of distraction that could potentially distract bus drivers while driving, including those that derive from the driving task itself, and those that derive from the additional requirements associated with bus operation, such as passenger and ticketing-related distractions. A taxonomy of the sources of bus driver distraction identified is presented, along with a discussion of proposed countermeasures designed to remove the sources identified or mitigate their effects on driver performance.     

Recently qualified drivers: a comparison of two methods of driving instruction

The progress of drivers in the year after passing the driving test has been evaluated in a number of studies undertaken in France and elsewhere. These studies have focused upon the technical and psychological difficulties that newly qualified drivers need to overcome before they come to consider themselves, and to be considered by others, as fully competent drivers. The quality of driving instruction seems to be crucial in determining the kinds of problems which new drivers must face and the time taken to achieve mastery.

Two methods of driving instruction were compared in terms of the problems encountered by learners after passing their driving test. The subjects were 170 drivers taught by the traditional ‘driving-test’ method and 269 who had taken an accelerated course of intensive instruction. Each driver was sent a series of questionnaires during the 10 months after they qualified. In addition to this form of continuous survey, an in-depth study of nine other new drivers was undertaken over the same period; their on-the-road behaviour was used to supplement information obtained from the questionnaires. The results of the research are discussed in relation to a variety of factors: level of driver confidence; ease of vehicle handling; problems acknowledged by drivers; drivers’ attitude towards road safety; progress made in the period following the driving test; need for further instruction; response to frustration and evaluation of aggressive tendencies.     

Role of lateral acceleration in curve driving: driver model and experiments on a real vehicle and a driving simulator

Experimental studies show that automobile drivers adjust their speed in curves so that maximum vehicle lateral accelerations decrease at high speeds. This pattern of lateral accelerations is described by a new driver model, assuming drivers control a variable safety margin of perceived lateral acceleration according to their anticipated steering deviations. Compared with a minimum time-to-lane-crossing (H. Godthelp, 1986) speed modulation strategy, this model, based on nonvisual cues, predicts that extreme values of lateral acceleration in curves decrease quadratically with speed, in accordance with experimental data obtained in a vehicle driven on a test track and in a motion-based driving simulator. Variations of model parameters can characterize "normal" or "fast" driving styles on the test track. On the simulator, it was found that the upper limits of lateral acceleration decreased less steeply when the motion cuing system was deactivated, although drivers maintained a consistent driving style. This is interpreted per the model as an underestimation of curvilinear speed due to the lack of inertial stimuli. Actual or potential applications of this research include a method to assess driving simulators as well as to identify driving styles for on-board driver aid systems.     

Attention decrease of drivers exposed to vibration from military vehicles when driving in terrain conditions

In this study, we analyzed the phenomenon of reduced attention for 11 subjects using a 6-degree-of-freedom synthetic vibration platform to simulate the vibration from terrain driving. Military vehicles are mainly used in terrain conditions, and drivers are exposed to whole-body vibrations for long periods of time. Drivers not only have trouble with comfort and health, they also suffer decreased attention. This decrease has a negative effect on driving. The vibration signal of a military vehicle on terrain is simulated using a synthetic vibration platform. Eleven subjects experienced these synthesized field-terrain vibrations while on the vibration platform performing a variety of perceptual and cognitive attention tests. The attention tests were divided into perceptual and cognitive, and the decrease in attention caused by vibration exposure and the exposure time was analyzed. From the results, automatic perceptual attention was not affected by vibration exposure. When the complexity of cognitive processing was increased during the attention test, the effects of vibration exposure became significant. The decrease in certain attention mechanisms was found when drivers were exposed to whole-body vibrations. Thus, it is expected that drivers are adversely affected when performing missions. We analyze the correlation between vibration exposure and attention decrease in this study, and the ability of the military vehicle driver to perform his mission can be predicted.     

Fifty years of driving safety research

OBJECTIVE: This brief review covers the 50 years of driving-related research published in Human Factors, its contribution to driving safety, and emerging challenges. BACKGROUND: Many factors affect driving safety, making it difficult to assess the impact of specific factors such as driver age, cell phone distractions, or collision warnings. METHOD: The author considers the research themes associated with the approximately 270 articles on driving published in Human Factors in the past 50 years. RESULTS: To a large extent, current and past research has explored similar themes and concepts. Many articles published in the first 25 years focused on issues such as driver impairment, individual differences, and perceptual limits. Articles published in the past 25 years address similar issues but also point toward vehicle technology that can exacerbate or mitigate the negative effect of these issues. Conceptual and computational models have played an important role in this research. CONCLUSION: Improved crash-worthiness has contributed to substantial improvements in driving safety over the past 50 years, but future improvements will depend on enhancing driver performance and perhaps, more important, improving driver behavior. Developing models to guide this research will become more challenging as new technology enters the vehicle and shifts the focus from driver performance to driver behavior. APPLICATION: Over the past 50 years, Human Factors has accumulated a large base of driving-related research that remains relevant for many of today's design and policy concerns.     

Research Issues in Smart Vehicles and Elderly Drivers: A Literature Review

This article reviewed both studies on general smart car technologies and human–computer interaction (HCI)/human–vehicle interaction studies that were published in journals and conferences so that the current status of research can be identified and future research directions can be suggested. Furthermore, previous studies on elderly drivers were reviewed, as these drivers could be the most vulnerable social group in terms of new technology acceptance. A total of 257 articles for HCI research and 45 articles for elderly drivers were selected and reviewed from 11,267 collected articles (2010–2014). According to the results, most articles were mainly related to safety and adaptive features (e.g., driver’s state recognition, vehicle surrounding monitoring, driver action-suggestion), and infotainment research in terms of HCI (e.g., information technology devices–vehicle interaction, vehicle–vehicle interaction) was relatively insufficient despite its high research demand. According to the results of the literature review and technological trends analysis based on previous technical road maps, from HCI/human factors engineering (HFE) perspectives, research related to “Assistance systems,” “Physiological & mental state recognition,” “Position sensor technology,” “Behavior recognition,” and “Infotainment” was suggested to HCI/HFE researchers for further research. In particular, HCI/HFE researchers need to focus on research on acceptable levels of automation, observing new driving behaviors, investigation of driver characteristics to develop personalized services, and new technology acceptance to develop and improve smart cars in the future.     

Estimation method for the consciousness level while driving vehicles

Recently, the driver's attention while driving a vehicle has to be taken seriously in a modernized society. Although some studies of attention while driving are being conducted now, the character of human activity is complicated for estimating attention while driving a vehicle. In the present study, the driver's attention was studied by driving performance and meandering of the vehicle. Two sets of drivers were used to compare with higher and lower states of consciousness. For driving performance, the degree of steering and the degree of acceleration were measured. For meandering, the shoulder line on the road was detected by a CCD camera to calculate the coordinates of the vehicles. These three values showed the dynamical degree of the driver's attention. The results show that the meandering values and the degree of steering values correlated with the degree of attention of the driver, and these results can be applied to make an alert system for drivers during decreased consciousness or concentration in order to realize a safe society for our modern roadways.     

Speech-based E-mail and driver behavior: effects of an in-vehicle message system interface

As mobile office technology becomes more advanced, drivers have increased opportunity to process information "on the move." Although speech-based interfaces can minimize direct interference with driving, the cognitive demands associated with such systems may still cause distraction. We studied the effects on driving performance of an in-vehicle simulated "E-mail" message system; E-mails were either system controlled or driver controlled. A high-fidelity, fixed-base driving simulator was used to test 19 participants on a car-following task. Virtual traffic scenarios varying in driving demand. Drivers compensated for the secondary task by adopting longer headways but showed reduced anticipation of braking requirements and shorter time to collision. Drivers were also less reactive when processing E-mails, demonstrated by a reduction in steering wheel inputs. In most circumstances, there were advantages in providing drivers with control over when E-mails were opened. However, during periods without E-mail interaction in demanding traffic scenarios, drivers showed reduced braking anticipation. This may be a result of increased cognitive costs associated with the decision making process when using a driver-controlled interface when the task of scheduling E-mail acceptance is added to those of driving and E-mail response. Actual or potential applications of this research include the design of speech-based in-vehicle messaging systems.