Effects of cognitive tasks on car drivers’ behaviors and physiological responses

The effects of drivers’ engagement in cognitive tasks (i.e., non-visual, cognitively loading activities unrelated to the task of driving) are debated and unclear. Numerous experiments show impaired driver behaviors, yet naturalistic studies typically do not find an increased crash risk. In the future, autonomous driving (AD) is expected to improve traffic safety while allowing safe engagement in cognitive (and other) tasks. Having the opportunity to perform non-driving related tasks while traveling may then motivate drivers to use AD, provided they can actually engage in the tasks. Unfortunately, research on drivers’ engagement in cognitive tasks suffers severe methodological limitations since reliable and unintrusive measures of cognitive load are lacking.The aim of this thesis is therefore to advance the understanding of task-induced cognitive load in the context of traffic safety. This aim is split into two objectives: A) to better understand how drivers’ involvement in cognitive tasks can affect safety-relevant driver behaviors and decisions and B) to provide methodological guidance about assessing cognitive load in drivers using physiological measures.To accomplish Objective A, effects of cognitive tasks on driver behaviors were studied during routine driving and in a safety-critical event in a driving simulator. Also, drivers’ ability to engage in a non-driving related task while using AD in real traffic was explored. In line with the cognitive control hypothesis (Engstr\uf6m et al., 2017), it was found that cognitive tasks negatively affected driver behaviors in situations where cognitive control was needed, for example in intersections—but not in a lead vehicle braking scenario where responses were triggered automatically by visual looming. It was also found that although the number of off-path glances decreased during cognitive load, the timing of the remaining glances was unaffected. Clearly, cognitive load has different effects on different mechanisms. When using AD, drivers were indeed capable of engaging in a non-driving related task—suggesting that AD will be able to fulfill drivers’ desire to perform such tasks while traveling, which may motivate AD usage and thus improve traffic safety (given that AD is truly safer than manual driving). Finally, a simulator study addressing Objective B showed that the measurability of cognitive load was greatly improved by recognizing that multiple coexisting mental responses give rise to different physiological responses. This approach can provide less context-dependent measurements and allows for a better, more detailed understanding of the effects of cognitive tasks.These findings can help improve traffic safety—both by being used in system development, and as part of the systems themselves

THE EFFECTS OF COMBINING REDUCED LUMINANCE AND INCREASED BLUR ON OLDER DRIVER SPEED AND VISUAL ACUITY

Drivers may be at more risk to themselves and other roadway users when vision is blurred or when luminance levels are reduced. Past research has investigated these visual conditions separately, finding that each degrades acuity without severely impairing steering ability. However, it is unknown how reduced luminance in combination with increased blur will affect driving performance. This study sought to quantify this combined effect on older adults\u27 comfortable driving speed and visual acuity by testing 10 participants in a driving simulator. The majority of the luminance and blur conditions are comparable to those the driving population may realistically encounter. Participants were asked to drive the speed at which they feel comfortable and could stay within their lane without using the speedometer. To ensure participants followed the instructions to stay in their lane, a percentage-of-time-in-lane measure was used to confirm no differences in steering performance existed across conditions. The older adult drivers only slowed down during the extreme blur condition; however, visual acuity was impaired by each manipulation. Interestingly, after the training conditions requiring a speed above 50 mph, drivers were given the opportunity to choose their speed and dramatically slowed down. This unexpected finding illustrates an important difference in what aging drivers choose to do in comparison with what they can do. This finding has important applied implications

The Effectiveness of Glare-Obscuring Glasses on Nighttime Driving Performance

Currently no driver-aid system effectively addresses glare-reduction for oncoming headlights. Glare at night has the ability to decrease our visual acuity and cause discomfort or pain. This decreased visual ability constitutes an increased risk for driver error and a potential roadway safety hazard. The severity of these detrimental effects has previously been shown to increase with driver age and is thought to be further exacerbated by the increased brightness of High Intensity Discharge (HID) headlights. In the current study, the effects of headlight glare from HID and halogen lights on driver performance was examined in a custom driving simulator. A novel polarized headlight glare-blocking system was also examined for its effectiveness in reducing headlight glare. Decreased visual field perception occurred across all age groups with the use of oncoming HID headlights compared to halogen headlights. In addition, older drivers\u27 performance on the visual awareness task was significantly decreased as compared to their younger counterparts. The performance-restoring effects of the headlight-blocking system were especially beneficial to older adults exposed to HID headlights, restoring visual field perceptual abilities to nearly that of the younger age group. As even brighter LED-based headlights reach the automotive market in the midst of an expanding older driver population, it is urged that automotive manufacturers consider glare-mitigation strategies when designing current headlight systems

Aerospace Medicine and Biology. A continuing bibliography with indexes

This bibliography lists 244 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1981. Aerospace medicine and aerobiology topics are included. Listings for physiological factors, astronaut performance, control theory, artificial intelligence, and cybernetics are included

Motorcycle Conspicuity: The Effects Of Age And Vehicular Daytime Running Lights

Research has shown that riding a motorcycle can potentially be much more dangerous than operating a conventional vehicle. There are factors inherent in driving or riding a small two wheeled vehicle, such as a motorcycle, moped or even bicycle that can potentially decrease their ability to be seen or noticed by other drivers. This disadvantage is reflected in the disproportionate over-representation of injuries and/or fatalities incurred by this particular driving group. This creates a significant problem which deserves dedicated evaluation as to causative factors and/or influential variables. The following research was conducted with intentions to investigate the topic of motorcycle conspicuity so as to further explain the variables which positively contribute to a motorcycle being seen and to supplement the body of knowledge that currently exists on this topic. This study specifically evaluated the influence of sex, age, motorcycle lighting conditions, and vehicular daytime running lights upon one\u27s ability to effectively detect a motorcycle within a high fidelity simulated environment. This research additionally sought to examine the feasibility and validity of using a novel fixed base high fidelity simulator for the evaluation of motorcycle conspicuity. The results from this research clearly indicate a link between vehicular DRLs and the effective detection of motorcycles and also support previous research as to the effectiveness of motorcycle DRLs. Additionally, these results suggest that as one ages, certain degradations in vision, cognition, and physiology occur which decrease one\u27s performance in detecting and responding to a motorcycle. These findings additionally provide support for the use of a high definition fixed base simulator as a valid technology for the evaluation of motorcycle conspicuity

The Influence on Road Safety Due to Driver Distraction from Outdoor Advertising: Case Study

This paper provides a review of current research on driver distraction, focusing on outdoor advertising. Also examined is whether, and to what degree, these degradations in driving performance translate into a decreased road safety. Disorders of the driver during driving can be divided into four basic groups: visual disturbances; The driver does not look at driving directions, hearing impairment; The driver is disturbed by a sound that does not pay attention to the current traffic situation, hand interference; The driver does not use both hands for steering with a steering wheel and a cognitive disorder; Not the driver's focus and indecision. Roadside advertising is intended to attract the driver's attention, which at a given moment reduces the driver's attention to the actual traffic situation and driving. A driver's disturbance may also be caused by roadside advertising in the event of a strong luminance of the advertised screens, talking about the blindness of the driver or in case of motion. The literature review, however, provides a possible proposal for the regulation of roadside advertising in such a way that it is not a disturbance of the driver or a possible non-visualization of vertical signalization. In the final section of the paper, recommendations for future research is provided

Understanding and Modeling the Human Driver

This paper examines the role of the human driver as the primary control element within the traditional driver-vehicle system. Lateral and longitudinal control tasks such as path-following, obstacle avoidance, and headway control are examples of steering and braking activities performed by the human driver. Physical limitations as well as various attributes that make the human driver unique and help to characterize human control behavior are described. Example driver models containing such traits and that are commonly used to predict the performance of the combined driver-vehicle system in lateral and longitudinal control tasks are identified.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65021/1/MacAdam_2003 VSD Understanding and Modelling the Driver.pd

Effect of Obstacle Type and Cognitive Task on Situation Awareness and Takeover Performance in Conditionally Automated Driving

In conditionally automated driving, several factors can affect the driver’s situation awareness and ability to take over control. To better understand the influence of some of these factors, 88 participants spent 20 minutes in a conditionally automated driving simulator. They had to react to four obstacles that varied in danger and movement. Half of the participants were required to engage in a verbal cognitive non-driving-related task. Situation awareness, takeover performance and physiological responses were measured for each situation. The results suggest that obstacle movement influences obstacle danger perception, situation awareness, and response time, while the latter is also influenced by obstacle danger. The cognitive verbal task also had an effect on the takeover response time. These results imply that the driver’s cognitive state and the driving situation (e.g. the movement/danger of entities present around the vehicle) must be considered when conveying information to drivers through in-vehicle interfaces

Quantifying Drivers\u27 Responses to Failures of Semi-autonomous Vehicle Systems

The number of vehicles on the road with advanced and automated driving support systems (DSSs) is increasing. However, there may be some issues related to the implementation of DSSs in vehicles. One of those issues caused by the automated DSSs relates to the drivers\u27 being out-of-the-loop. As drivers\u27 roles are transitioned from system operators to systems supervisors (as in autonomous vehicles), drivers\u27 situation awareness of the driving surroundings may decrease which could negatively affect their responses when they need to take control of the vehicle from the malfunctioned (or failed) DSSs. Additionally, with both the adaptive cruise control (ACC) and lane keeping (LK) systems engaged, the longitudinal and lateral positions of the vehicle are under the control of automation and the vehicle becomes a semi-autonomous vehicle (i.e., the vehicles are now at level 2 automation based on the definitions of the National Highway Traffic Safety Administration taxonomy for automation). In semi-autonomous vehicles, drivers are more likely to interact with non-driving tasks and engage in risky behaviors (e.g., long glances away from the forward road way), as the demand of the driving tasks is much lower than manually driving and driving with only ACC engaged. This may worsen drivers\u27 responses to the failures of semi-autonomous vehicle components, when drivers are engaged in non-driving tasks. The objectives of this dissertation were to assess how drivers respond to the failures of the LK system with different levels of vehicle automation and to assess the effects of drivers\u27 engagements in non-driving tasks on their behaviors associated with a failure of the LK system. This dissertation also investigates if a lane departure warning would mitigate the negative effects of out-of-the-loop problem brought on by automation and improve drivers\u27 responses to the LK system fails especially when drivers are engaging both the ACC and LK systems. Additionally, the relationships between drivers\u27 personalities and attitudes toward automation and their responses during the failure of the LK system were evaluated. Three experiments were used to address the dissertation research objectives. The results demonstrate that drivers in semi-autonomous vehicles (level 2 automation vehicles) have less safe behaviors (e.g., more engagement in non-driving tasks and longer glances away from the roadway) than their peers who were manually driving the vehicles. During the failures of the LK systems, drivers in semi-autonomous vehicles have worse driving behaviors compared to their counterparts driving manually or driving with the LK system engaged. Non-driving tasks also increase drivers\u27 reaction time to safety critical events in semi-autonomous vehicles. However, the effects of audible lane departure warnings on drivers\u27 responses to potential lane departure events were not consistent between the level 0 automation condition (i.e., the manual driving condition) and level 2 automation condition (i.e., the automated driving condition). Overall, audible warnings with 1.48 s prediction time assist drivers\u27 in responding to the lane departure events following the failure of the LK system in semi-autonomous vehicles. However, the effects of audible warnings on drivers\u27 responses to the potential lane departure events are divergent when drivers are manually operating the vehicles. Though audible warnings as one type of discrete feedback of automation activities help drivers improve their responses to safety critical events in semi-autonomous vehicles, they cannot solve the out-of-control loop problem caused by automation. Future work should evaluate if continuous feedback could address the out-of-control loop problem brought on by automation and keep drivers in the vehicle control loop in semi- or fully- autonomous vehicles

Varieties of interaction: from User Experience to Neuroergonomics:On the occasion of the Human Factors and Ergonomics Society Europe Chapter Annual Meeting in Rome, Italy 2017

Proceedings of the HFES European Chapter conferenc