Examining cognitive interference and adaptive safety behaviours in tactical vehicle control

Young Novice Drivers' Cognitive Distraction Detection: Comparing Support Vector Machines and Random Forest Model of Vehicle Control Behavior

The use of mobile phones has become one of the major threats to road safety, especially in young novice drivers. To avoid crashes induced by distraction, adaptive distraction mitigation systems have been developed that can determine how to detect a driver's distraction state. A driving simulator experiment was conducted in this paper to better explore the relationship between drivers' cognitive distractions and traffic safety, and to better analyze the mechanism of distracting effects on young drivers during the driving process. A total of 36 participants were recruited and asked to complete an n-back memory task while following the lead vehicle. Drivers' vehicle control behavior was collected, and an ANOVA was conducted on both lateral driving performance and longitudinal driving performance. Indicators from three aspects, i.e., lateral indicators only, longitudinal indicators only, and combined lateral and longitudinal indicators, were inputted into both SVM and random forest models, respectively. Results demonstrated that the SVM model with parameter optimization outperformed the random forest model in all aspects, among which the genetic algorithm had the best parameter optimization effect. For both lateral and longitudinal indicators, the identification effect of lateral indicators was better than that of longitudinal indicators, probably because drivers are more inclined to control the vehicle in lateral operation when they were cognitively distracted. Overall, the comprehensive model built in this paper can effectively identify the distracted state of drivers and provide theoretical support for control strategies of driving distraction.

The Effects of Vehicle Automation on Driver Engagement: The Case of Adaptive Cruise Control and Mind Wandering

OBJECTIVE

This field study examined the effects of adaptive cruise control (ACC) on mind wandering prevalence.

BACKGROUND

ACC relieves the driver of the need to regulate vehicle speed and following distance, which may result in safety benefits. However, if ACC reduces the amount of attentional resources drivers must devote to driving, then drivers who use ACC may experience increased periods of mind wandering, which could reduce safety.

METHODS

Participants drove a prescribed route on a public road twice, once using ACC and once driving manually. Mind wandering rates were assessed throughout the drive using auditory probes, which occurred at random intervals and required the participant to indicate whether or not they were mind wandering. Measures of physiological arousal and driving performance were also recorded.

RESULTS

No evidence of increased mind wandering was found when drivers used ACC. In fact, female drivers reported reduced rates of mind wandering when driving with ACC relative to manual driving. Driving with ACC also tended to be associated with increased physiological arousal and improved driving behavior.

CONCLUSION

Use of ACC did not encourage increased mind wandering or negatively affect driving performance. In fact, the results indicate that ACC may have positive effects on driver safety among drivers who have limited experience with the technology.

APPLICATION

Driver characteristics, such as level of experience with in-vehicle technology and gender, should be considered when investigating driver engagement during ACC use. Field research on vehicle automation may provide valuable insights over and above studies conducted in driving simulators.

Effects of Mobile Computer Terminal Configuration and Level of Driving Control on Police Officers' Performance and Workload

OBJECTIVE

The objective of this study was to assess police officers' performance and workload in using two mobile computer terminal (MCT) configurations under operational and tactical driving conditions.

BACKGROUND

Crash reports have identified in-vehicle distraction to be a major cause of law enforcement vehicle crashes. The MCT has been found to be the most frequently used in-vehicle technology and the main source of police in-vehicle distraction.

METHOD

Twenty police officers participated in a driving simulator-based assessment of driving behavior, task completion time, and perceived workload with two MCT configurations under operational and tactical levels of driving.

RESULTS

The findings revealed that using the MCT configuration with speech-based data entry and head-up display location while driving improved driving performance, decreased task completion time, and reduced police officers' workload as compared to the current MCT configuration used by police departments. Officers had better driving but worse secondary task performance under the operational driving as compared to the tactical driving condition.

CONCLUSION

This study provided an empirical support for use of an enhanced MCT configuration in police vehicles to improve police officers' safety and performance. In addition, the findings emphasize the need for more training to improve officers' tactical driving skills and multitasking behavior.

APPLICATION

The findings provide guidelines for vehicle manufacturers, MCT developers, and police agencies to improve the design and implementation of MCTs in police vehicles considering input modality and display eccentricity, which are expected to increase officer and civilian safety.

Tactical and strategic driving behaviour in older drivers: The importance of readiness to change

The aim of this study was to explore the way in which reports of strategic and tactical driving self-regulation are influenced by readiness to change driving behaviour in older men and women, either reporting or not reporting modification of driving behaviour for health-related reasons, and/or increased driving difficulty. Current Australian drivers aged over 60 years (N = 258) responded to a self-report questionnaire. Hierarchical regression analyses indicated increased use of tactical behaviours were associated with greater driving difficulty, more readiness to change and male gender (R² = 23.2%) . These effects were moderated by a significant association between readiness to change, driving modifications for health reasons and age (R²_chg = 2.9%). Greater readiness to change was associated with increased use of tactical behaviours for older drivers who did not modify driving for health reasons, independent of ageIndependent of age. This association was also found for younger old drivers with health difficulties, but not for older old drivers with health difficulties. Hierarchical regression indicated that greater readiness to change, increased driving difficulty, female gender and modification of driving for health reasons were associated with reports of increased strategic self-regulation (R² = 50.8%). These effects were moderated by readiness to change and age, and readiness to change and gender (R²_chg = 2.1%). The association between readiness to change and strategic self-regulation was stronger for women than men, and the strength of this association became substantially stronger with increasing age. It was concluded that readiness to change driving behaviour may promote different forms of driving self-regulation for different individuals, and that older drivers may use the different forms of driving self-regulation independently of one another.

Does Talking on a Cell Phone, With a Passenger, or Dialing Affect Driving Performance? An Updated Systematic Review and Meta-Analysis of Experimental Studies

Objective An up-to-date meta-analysis of experimental research on talking and driving is needed to provide a comprehensive, empirical, and credible basis for policy, legislation, countermeasures, and future research. Background The effects of cell, mobile, and smart phone use on driving safety continues to be a contentious societal issue. Method All available studies that measured the effects of cell phone use on driving were identified through a variety of search methods and databases. A total of 93 studies containing 106 experiments met the inclusion criteria. Coded independent variables included conversation target (handheld, hands-free, and passenger), setting (laboratory, simulation, or on road), and conversation type (natural, cognitive task, and dialing). Coded dependent variables included reaction time, stimulus detection, lane positioning, speed, headway, eye movements, and collisions. Results The overall sample had 4,382 participants, with driver ages ranging from 14 to 84 years ( M = 25.5, SD = 5.2). Conversation on a handheld or hands-free phone resulted in performance costs when compared with baseline driving for reaction time, stimulus detection, and collisions. Passenger conversation had a similar pattern of effect sizes. Dialing while driving had large performance costs for many variables. Conclusion This meta-analysis found that cell phone and passenger conversation produced moderate performance costs. Drivers minimally compensated while conversing on a cell phone by increasing headway or reducing speed. A number of additional meta-analytic questions are discussed. Application The results can be used to guide legislation, policy, countermeasures, and future research.

Trade-off between jerk and time headway as an indicator of driving style

Variation in longitudinal control in driving has been discussed in both traffic psychology and transportation engineering. Traffic psychologists have concerned themselves with “driving style”, a habitual form of behavior marked by it’s stability, and its basis in psychological traits. Those working in traffic microsimulation have searched for quantitative ways to represent different driver-car systems in car following models. There has been unfortunately little overlap or theoretical consistency between these literatures. Here, we investigated relationships between directly observable measures (time headway, acceleration and jerk) in a simulated driving task where the driving context, vehicle and environment were controlled. We found individual differences in the way a trade-off was made between close but jerky vs. far and smooth following behavior. We call these “intensive” and “calm” driving, and suggest this trade-off can serve as an indicator of a possible latent factor underlying driving style. We posit that pursuing such latent factors for driving style may have implications for modelling driver heterogeneity across various domains in traffic simulation.

Effects of Cognitive Load on Driving Performance: The Cognitive Control Hypothesis

OBJECTIVE

The objective of this paper was to outline an explanatory framework for understanding effects of cognitive load on driving performance and to review the existing experimental literature in the light of this framework.

BACKGROUND

Although there is general consensus that taking the eyes off the forward roadway significantly impairs most aspects of driving, the effects of primarily cognitively loading tasks on driving performance are not well understood.

METHOD

Based on existing models of driver attention, an explanatory framework was outlined. This framework can be summarized in terms of the cognitive control hypothesis: Cognitive load selectively impairs driving subtasks that rely on cognitive control but leaves automatic performance unaffected. An extensive literature review was conducted wherein existing results were reinterpreted based on the proposed framework.

RESULTS

It was demonstrated that the general pattern of experimental results reported in the literature aligns well with the cognitive control hypothesis and that several apparent discrepancies between studies can be reconciled based on the proposed framework. More specifically, performance on nonpracticed or inherently variable tasks, relying on cognitive control, is consistently impaired by cognitive load, whereas the performance on automatized (well-practiced and consistently mapped) tasks is unaffected and sometimes even improved.

CONCLUSION

Effects of cognitive load on driving are strongly selective and task dependent.

APPLICATION

The present results have important implications for the generalization of results obtained from experimental studies to real-world driving. The proposed framework can also serve to guide future research on the potential causal role of cognitive load in real-world crashes.

Evaluation of Strategies for Integrated Classification of Visual-Manual and Cognitive Distractions in Driving

BACKGROUND

Prior studies have demonstrated unique driver behavior outcomes when visual and cognitive distraction occurs simultaneously as compared to the occurrence of one form of distraction alone. This situation implies additional complexity for the design of robust distraction detection systems and vehicle automation for hazard mitigation.

OBJECTIVE

This study evaluated the effectiveness of two distraction classification strategies: (a) a "two-stage" classifier, first detecting visual-manual distraction and then identifying dual or cognitive distraction states, and (b) a "direct-mapping" classifier developed to identify all distraction states at the same time.

METHOD

Driving performance data were collected on 20 participants under different known states of distraction (none, visual-manual, cognitive, and combined). A support vector machine (SVM) was used as a base algorithm for both classifiers and performance data as well as the level of driving control (tactical and operational), which served as inputs and modifiers to the classification process.

RESULTS

The two-stage strategy was found to be sensitive for identifying states of visual-manual distraction; however, the strategy also produced a higher false alarm rate than direct-mapping. Consideration of driving control levels during classification also improved classification accuracy. Future work needs to account for strategic levels of vehicle control.

Texting while driving using Google Glass™: Promising but not distraction-free

Texting while driving is risky but common. This study evaluated how texting using a Head-Mounted Display, Google Glass, impacts driving performance. Experienced drivers performed a classic car-following task while using three different interfaces to text: fully manual interaction with a head-down smartphone, vocal interaction with a smartphone, and vocal interaction with Google Glass. Fully manual interaction produced worse driving performance than either of the other interaction methods, leading to more lane excursions and variable vehicle control, and higher workload. Compared to texting vocally with a smartphone, texting using Google Glass produced fewer lane excursions, more braking responses, and lower workload. All forms of texting impaired driving performance compared to undistracted driving. These results imply that the use of Google Glass for texting impairs driving, but its Head-Mounted Display configuration and speech recognition technology may be safer than texting using a smartphone.

Texting while driving: is speech-based text entry less risky than handheld text entry?

Research indicates that using a cell phone to talk or text while maneuvering a vehicle impairs driving performance. However, few published studies directly compare the distracting effects of texting using a hands-free (i.e., speech-based interface) versus handheld cell phone, which is an important issue for legislation, automotive interface design and driving safety training. This study compared the effect of speech-based versus handheld text entries on simulated driving performance by asking participants to perform a car following task while controlling the duration of a secondary text-entry task. Results showed that both speech-based and handheld text entries impaired driving performance relative to the drive-only condition by causing more variation in speed and lane position. Handheld text entry also increased the brake response time and increased variation in headway distance. Text entry using a speech-based cell phone was less detrimental to driving performance than handheld text entry. Nevertheless, the speech-based text entry task still significantly impaired driving compared to the drive-only condition. These results suggest that speech-based text entry disrupts driving, but reduces the level of performance interference compared to text entry with a handheld device. In addition, the difference in the distraction effect caused by speech-based and handheld text entry is not simply due to the difference in task duration.

Failure to see money on a tree: inattentional blindness for objects that guided behavior

How is it possible to drive home and have no awareness of the trip? We documented a new form of inattentional blindness in which people fail to become aware of obstacles that had guided their behavior. In our first study, we found that people talking on cell phones while walking waited longer to avoid an obstacle and were less likely to be aware that they had avoided an obstacle than other individual walkers. In our second study, cell phone talkers and texters were less likely to show awareness of money on a tree over the pathway they were traversing. Nonetheless, they managed to avoid walking into the money tree. Perceptual information may be processed in two distinct pathways - one guiding behavior and the other leading to awareness. We observed that people can appropriately use information to guide behavior without awareness.

Pursue or shoot? Effects of exercise-induced fatigue on the transition from running to rifle shooting in a pursuit task

To investigate to what degree exercise-induced fatigue influences behavioural choices, participants' transition from running to rifle shooting in a pursue-and-shoot task was assessed. Participants ran on a treadmill and chased a target in a virtual environment and were free to choose when to stop the treadmill and shoot at the target. Fatigue increased progressively throughout the 20-minute test. Results indicated that shooting accuracy was not affected by fatigue. However, the distance to the target at which participants decided to shoot showed a U-shaped relationship with fatigue, R(2) = 0.884, p = 0.013. At low fatigue levels (ratings of perceived exertion [RPE] < 6.5), the distance to the target at which participants shot decreased, whereas at higher fatigue levels (RPE > 6.5) shooting distance increased again. At high levels of fatigue, participants stopped running sooner, aimed at the target longer and shot less often. Findings indicate that physiological parameters influence not only perception but also actual transitions between different actions.

Examining the Efficacy of Training Interventions in Improving Older Driver Performance

An increasing number of commercial training products claim to improve older driver performance by training underlying cognitive abilities. However, research examining transfer of such training to driving performance is limited. The current study examined whether 16 hours of training on a commercial training package improved older adults’ performance in a high-fidelity driving simulator. Data showed no differential improvements between the training group and a control group on any driving performance measure following training. The commercial training program did not improve the simulated driving performance of older adults.

Walking and talking: dual-task effects on street crossing behavior in older adults

The ability to perform multiple tasks simultaneously has become increasingly important as technologies such as cell phones and portable music players have become more common. In the current study, we examined dual-task costs in older and younger adults using a simulated street crossing task constructed in an immersive virtual environment with an integrated treadmill so that participants could walk as they would in the real world. Participants were asked to cross simulated streets of varying difficulty while either undistracted, listening to music, or conversing on a cell phone. Older adults were more vulnerable to dual-task impairments than younger adults when the crossing task was difficult; dual-task costs were largely absent in the younger adult group. Performance costs in older adults were primarily reflected in timeout rates. When conversing on a cell phone, older adults were less likely to complete their crossing compared with when listening to music or undistracted. Analysis of time spent next to the street prior to each crossing, where participants were presumably analyzing traffic patterns and making decisions regarding when to cross, revealed that older adults took longer than younger adults to initiate their crossing, and that this difference was exacerbated during cell phone conversation, suggesting impairments in cognitive planning processes. Our data suggest that multitasking costs may be particularly dangerous for older adults even during everyday activities such as crossing the street.

Mind wandering behind the wheel: performance and oculomotor correlates

OBJECTIVE

An experiment studied the frequency and correlates of driver mind wandering.

BACKGROUND

Driver mind wandering is associated with risk for crash involvement. The present experiment examined the performance and attentional changes by which this effect might occur.

METHOD

Participants performed a car-following task in a high-fidelity driving simulator and were asked to report any time they caught themselves mind wandering. Vehicle control and eye movement data were recorded.

RESULTS

As compared with their attentive performance, participants showed few deficits in vehicle control while mind wandering but tended to focus visual attention narrowly on the road ahead.

CONCLUSION

Data suggest that mind wandering can engender a failure to monitor the environment while driving.

APPLICATION

Results identify behavioral correlates and potential risks of mind wandering that might enable efforts to detect and mitigate driver inattention.

Combining cognitive and visual distraction: less than the sum of its parts

Driver distraction has become a leading cause of motor-vehicle crashes. Although visual and cognitive distraction has been studied extensively, relatively little research has addressed their combined effects on drivers' behavior. To fill this gap, a medium-fidelity simulator study examined the driver behavior before, during and after three types of distraction. Driving without distraction was compared to visual distraction, cognitive distraction, and combined visual and cognitive distraction. The results show that the visual and combined distraction both impaired vehicle control and hazard detection and resulted in frequent, long off-road glances. The combined distraction was less detrimental than visual distraction alone. Cognitive distraction made steering less smooth, but improved lane maintenance. All distractions caused gaze concentration and slow saccades when drivers looked at the roadway, and cognitive and combined distraction increased blink frequency. Steering neglect, under-compensation, and over-compensation were three typical steering failures that were differentially associated with the different distractions: steering neglect and over-compensation with visual distraction and under-compensation with cognitive distraction. Overall, visual distraction interferes with driving performance more than cognitive distraction, and visual distraction dominates the performance decrements during combined distraction. These results suggest that minimizing visual demand is particularly important in the design of in-vehicle systems and in the development of distraction countermeasures.

Are providers more likely to contribute to healthcare disparities under high levels of cognitive load? How features of the healthcare setting may lead to biases in medical decision making

Systematic reviews of healthcare disparities suggest that clinicians' diagnostic and therapeutic decision making varies by clinically irrelevant characteristics, such as patient race, and that this variation may contribute to healthcare disparities. However, there is little understanding of the particular features of the healthcare setting under which clinicians are most likely to be inappropriately influenced by these characteristics. This study delineates several hypotheses to stimulate future research in this area. It is posited that healthcare settings in which providers experience high levels of cognitive load will increase the likelihood of racial disparities via 2 pathways. First, providers who experience higher levels of cognitive load are hypothesized to make poorer medical decisions and provide poorer care for all patients, due to lower levels of controlled processing (H1). Second, under greater levels of cognitive load, it is hypothesized that healthcare providers' medical decisions and interpersonal behaviors will be more likely to be influenced by racial stereotypes, leading to poorer processes and outcomes of care for racial minority patients (H2). It is further hypothesized that certain characteristics of healthcare settings will result in higher levels of cognitive load experienced by providers (H3). Finally, it is hypothesized that minority patients will be disproportionately likely to be treated in healthcare settings in which providers experience greater levels of cognitive load (H4a), which will result in racial disparities due to lower levels of controlled processing by providers (H4b) and the influence of racial stereotypes (H4c).The study concludes with implications for research and practice that flow from this framework.

Effects of in-car support on mental workload and driving performance of older drivers

OBJECTIVE

This study examined the extent to which driving performance of 10 older (70-88 years old) and 30 younger participants (30-50 years old) improves as a result of support by a driver assistance system.

BACKGROUND

Various studies have indicated that advanced driver assistance systems (ADAS) may provide tailored assistance for older drivers and thereby improve their safe mobility.

METHOD

While drivers followed an urban route in a driving simulator, an ADAS provided them with prior knowledge on the next intersection. The system was evaluated in terms of effects on workload and safety performance.

RESULTS

Messages informing drivers about the right-of-way regulation, obstructed view of an intersection, and safe gaps to join or cross traffic streams led to safer driving performance. A message regarding an unexpected one-way street led to fewer route errors. In general, effects were the same for all age groups. Workload was not reduced by the support system.

CONCLUSION

The evaluated support system shows promising effects for all age groups. Longer evaluation periods are needed to determine long-term effects.

APPLICATION

The messages provided by the evaluated system are currently not provided by existing ADAS such as advanced cruise control and navigation systems, but they could possibly be added to them in the future.

Skill acquisition while operating in-vehicle information systems: interface design determines the level of safety-relevant distractions

OBJECTIVE

This study tested whether the ease of learning to use human-machine interfaces of in-vehicle information systems (IVIS) can be assessed at standstill.

BACKGROUND

Assessing the attentional demand of IVIS should include an evaluation of ease of learning, because the use of IVIS at low skill levels may create safety-relevant distractions.

METHOD

Skill acquisition in operating IVIS was quantified by fitting the power law of practice to training data sets collected in a driving study and at standstill. Participants practiced manual destination entry with two route guidance systems differing in cognitive demand. In Experiment 1, a sample of middle-aged participants was trained while steering routes of varying driving demands. In Experiment 2, another sample of middle-aged participants was trained at standstill.

RESULTS

In Experiment 1, display glance times were less affected by driving demands than by total task times and decreased at slightly higher speed-up rates (0.02 higher on average) than task times collected at standstill in Experiment 2. The system interface that minimized cognitive demand was operated more quickly and was easier to learn. Its system delays increased static task times, which still predicted 58% of variance in display glance times compared with even 76% for the second system.

CONCLUSION

The ease of learning to use an IVIS interface and the decrease in attentional demand with training can be assessed at standstill.

APPLICATION

Fitting the power law of practice to static task times yields parameters that predict display glance times while driving, which makes it possible to compare interfaces with regard to ease of learning.

Driver-initiated distractions: examining strategic adaptation for in-vehicle task initiation

Today, drivers are faced with many in-vehicle activities that are potentially distracting. In many cases, they are not passive recipients of these tasks; rather, drivers decide whether or not (or how) to perform them. In this study, we examined whether drivers, given knowledge of the upcoming road demands, would strategically delay performing in-vehicle activities until demands were reduced. Twenty drivers drove an instrumented van around a closed track that was divided into sections of varying demands and difficulty. Drivers were asked to perform one of four in-vehicle tasks (e.g., phone conversation; read a text message; find an address; pick up an object on the floor); however, they were free to decide when to initiate these tasks, provided they finish them before a given deadline. Although drivers were fully aware of the relative demands of the road, they did not tend to strategically postpone tasks--a finding that was consistent across the different tasks (p >.05). Rather, drivers tended to initiate tasks regardless of the current driving conditions. This strategy frequently led to driving errors. Given the control that drivers have over many in-vehicle distractions, interventions that focus on strategic decisions and planning may have merit.