In-vehicle Display Research Articles

Cost of Warning of Unseen Threats: Unintended Consequences of Connected Vehicle Alerts

One goal of the connected vehicle program is to raise the situation awareness of drivers to unseen events in the driving environment. Warnings of unseen threats may prompt a directed visual search for that threat at the expense of overlooking other intervening threats along the way. This study assessed the distraction potential of alerts to unseen threats. Twenty-two participants drove an instrumented vehicle on a closed course and encountered threat situations, such as a car entering the road from a side road obstructed from the driver's view. On each pass, there were two sandbags that served as secondary threats, and the driver was instructed to press a response button whenever one was detected. The control condition bags were placed at locations on the course where the driver was undistracted and encountered no primary threats. The threat bags were positioned so that they became visible shortly after the warning of a primary threat appeared on an in-vehicle display but before the primary threat became visible. The results showed that advance warnings improved primary threat detection time. That is, when drivers were given advance warning of the presence of an upcoming threat, the drivers identified the presence of the threat sooner than when no warning was given. Unfortunately, this facilitation came at a cost of reduced detection distance and reaction time to the secondary threats that were present in the roadway. Future research should investigate whether this effect persists for more critical secondary threats.

Effects of adaptive cruise control and highly automated driving on workload and situation awareness: A review of the empirical evidence

Adaptive cruise control (ACC), a driver assistance system that controls longitudinal motion, has been introduced in consumer cars in 1995. A next milestone is highly automated driving (HAD), a system that automates both longitudinal and lateral motion. We investigated the effects of ACC and HAD on drivers’ workload and situation awareness through a meta-analysis and narrative review of simulator and on-road studies. Based on a total of 32 studies, the unweighted mean self-reported workload was 43.5% for manual driving, 38.6% for ACC driving, and 22.7% for HAD (0%=minimum, 100=maximum on the NASA Task Load Index or Rating Scale Mental Effort). Based on 12 studies, the number of tasks completed on an in-vehicle display relative to manual driving (100%) was 112% for ACC and 261% for HAD. Drivers of a highly automated car, and to a lesser extent ACC drivers, are likely to pick up tasks that are unrelated to driving. Both ACC and HAD can result in improved situation awareness compared to manual driving if drivers are motivated or instructed to detect objects in the environment. However, if drivers are engaged in non-driving tasks, situation awareness deteriorates for ACC and HAD compared to manual driving. The results of this review are consistent with the hypothesis that, from a Human Factors perspective, HAD is markedly different from ACC driving, because the driver of a highly automated car has the possibility, for better or worse, to divert attention to secondary tasks, whereas an ACC driver still has to attend to the roadway.

Impact of In-Vehicle Displays Location Preferences on Drivers' Performance and Gaze

Advanced driver assistance systems (ADAS) and driver information systems (DIS) do not always comply with the intended driver safety enhancement. Even if they aim to augment the driver's awareness of the surrounding environment, perceiving this information requires the occasional attention diversion from the road, which could lead to a loss of vehicle control if the total eyes-off-road time exceeds the National Highway Traffic Safety Administration (NHTSA) recommendation for glances away from the roadway. Additionally, technologies that can be found in other mobile environments, smartphones, and tablets are increasingly being integrated into cars, providing a necessary facet of study and continued research in their effects. We addressed this question by analyzing differential preferences for the layout of DIS and ADAS compared with existing ones through a card-sorting experiment. To validate our data, we additionally studied the drivers' performance and gaze with the preferred locations for in-vehicle information through gaze location and speed metrics measurements. Our validation process showed that the time the drivers needed to find the conveyed information in the preferred layout was within the recommended time of the NHTSA Guidelines. Drivers' preferences with regard to the functional layout of current DIS and ADAS compared with existing ones did not essentially differ from the layouts that are currently on the market. However, including mobile applications and social media in a vehicular context was not considered necessary.

In-vehicle display HMI safety evaluation using a driving simulator

Recently, telematics services and in-vehicle display devices such as the CNS (Car Navigation System) have become new causes of traffic accidents. These accidents are caused by ‘Inattention’ from the increase of the driver’s mental workload while he/she is driving. The driver of a vehicle (except for emergency or police vehicles) must not use a hand-held mobile phone while the vehicle is moving. To address this problem, Australia, England, Italy, Brazil and some states in the US have banned the use of hand-held mobile devices during driving. However, there are no restrictions on the use of in-vehicle displays or on the display’s positions. The position of a navigation system in a vehicle should be assessed objectively, and the effect of the position on the driver’s attention should be studied. Some existing research reports that in-vehicle distraction not only leads to reduced speeds and more frequent lane switching, but also more gazing by the driver to the centre of the road. In this study, to develop an assessment method and to propose the proper position of a CNS, an experiment is carried out in a driving simulator environment. Different methods to track the gaze and physical parameters of the driver are used for HMI (Human-Machine Interface) assessment. The experiment is carried out in a driving simulator to observe the glancing distribution during driving according to the position of the navigation system. Fourteen subjects participated in this experiment. Changes in subjects’ physiological signals and glancing distribution rates were collected.

Text Readability and Drivers’ Reading Time

Internet access, vehicle diagnostics, and real-time communication are becoming increasingly common in all vehicles and the complexity of the information displayed is a major concern. Current guidelines focus on the number of characters in a text message, but other measures of text readability might be more sensitive. This study examined how well different metrics of text readability predict the time it takes a driver to read a message on an in-vehicle display. Participants completed reading tasks while seated in the driver’s seat of a driving simulator. Occlusion goggles were used to mimic the timesharing between the driving task and the secondary reading tasks, according to the ISO 16673 (2007) guidelines. The results showed that message length (number of characters) predicts the total time spent on the task (Total Shutter Open Time [TSOT]) and that the combination of number of words in the message and Shannon entropy of the message predicts TSOT only as well as number of characters alone. Applying the model human processor calculations of reading rates (Card, Moran, & Newell, 1983) showed that participants likely read the messages word-byword in successive saccades, instead of letter-by-letter or phrase-by-phrase. Findings provide direction for more in-depth lexical analyses of text readability related to in-vehicle displays.

승용차 글라스루프를 활용한 어린이용 별자리 콘텐츠 디자인

최근 캠핑 등 가족단위 여가생활이 늘어나게 되면서 어린아이들이 차를 타고 이동하는 횟수가 잦아지고 그에 따라 차 안에서 머무는 시간이 길어지게 되었다. 신체활동이 활발한 어린이들은 자동차 탑승 시 공간의 제약과 안전상의 이유로 움직임에 제한을 받고 있다. 한정된 공간에서 오랫동안 머무는 것에 대한 지루함과 답답함을 해소하기 위해 국내외 자동차 업체들은 넓은 시야 확보가 가능한 글라스루프를 적용한 차들을 선보이고 있다. 또한 IT기술이 접목된 스마트카 연구와 도어창문을 디스플레이로 활용하는 연구가 진행되고 있는 것을 보면 글라스루프도 스크린으로 활용될 수 있는 잠재가능성이 충분하다 할 수 있다. 이에 본 연구에서는 차량 내 디스플레이 적용 사례와 스마트 기기용 별자리 애플리케이션을 벤치마킹하고, 자가용으로 이동이 잦은 부모와 어린이를 대상으로 사용자 조사를 실시하여 어린이를 고려한 별자리학습 콘텐츠의 차량 글라스루프 적용 방식과 기본적인 인터랙션 방식을 도출, 제안하였다. Recently, the time in which children moves by car become frequent, they stay longer in the car because leisure life including camping and etc. increased. Children whose physical activities are active were subject to restriction because of the limited car boarding visual space and on security. Because of limited space in cars, domestic and foreign automotive companies show the different glass roof applied in cars that exhibited wide clear view in order to remove tedious and stuffy of children while they stay for a long time inside the car. In addition, the potential probability in which the Smart Car that the IT technology is grafted research and research that it utilizes the door window glass as the display is progressed and which the glass roof can be used as the screen can be sufficient. In this study, the in-vehicle display application case and Smart Devices constellation application were benchmarked. The car glass roof application method of the constellation studying content which performed the user survey for the child by the car with the parents whose movement is frequent and considers the child and fundamental interaction way tried to be drawn and we try to propose.

인지부하가 시각주의와 운전수행도에 미치는 영향에 관한 연령대별 분석

Visual demands associated with in-vehicle display usage and text messaging distract a driver’s visual attention from the roadway. To minimize eyes-off-the-road demands, voice interaction systems are widely introduced. Under cognitively distracted condition, however, awareness of the operating environment will be degraded although the driver remains oriented to the roadway. It is also know that the risk of inattentive driving varies with age, thus systematic analysis of driving risks is required for the older drivers. This paper aims to understand the age-related driving performance degradation and visual attention changes under auditory cognitive demand which consists of three graded levels of cognitive complexity. In this study, two groups, aged 25-35 and 60-69, engaged in a delayed auditory recall task, so called N-back task, while driving a simulated highway. Comparisons of younger and older drivers’ driving performance including mean speed, speed variability and standard deviation of lane position, and gaze dispersion changes, which consist of x-axis and y-axis of visual attention, were conducted. As a result, it was observed that gaze dispersion decreased with each level of demand, demonstrating that these indices can correctly rank order cognitive workload. Moreover, gaze dispersion change patterns were quite consistent in younger and older age groups. Effects were also observed on driving performance measures, but they were subtle, nonlinear, and did not effectively differentiate the levels of cognitive workload.

Assessment of risky driving caused by the amount of time focused on an in-vehicle display system

Korea is currently experiencing a rapidly increasing distribution rate of in-vehicle display devices, such as navigation or DMB displays, owing to remarkable advances in IT. At the same time, the number of traffic accidents and traffic violations is increasing due to the distraction of drivers’ attention by such devices. In particular, in-vehicle display devices such as navigation systems temporarily distract drivers’ visual or cognitive attention when they perform a unit task. Accordingly, it is necessary to prepare adequate standards to regulate in-vehicle display devices, especially in Korea. There are few empirical studies that have employed experiments to support such regulation. In this study, an experiment was conducted using a driving simulator to establish the proper standards regarding the maximum distraction time per unit task that can be allowed without causing any disturbance in safe driving. A total of 25 participants participated in the experiment. The distraction time was controlled by asking participants to perform the two tasks at once: while participants were driving as a primary task, they performed secondary task that count the number of intersections between the start point and the arrival point displayed on the screen. The results showed that the 2.0 second condition differed from the controlled condition in the deviation in the distance from the preceding vehicle, speed, and steering wheel movement, whereas there were no differences between the controlled condition and the 1.0 or 1.5 second condition. Finally, the limitations of the study and the implications of the findings with regard to future studies and application of the Korean version of guidelines for in-vehicle display devices are discussed.

Evaluation of Driver Performance and Distraction during use of in-vehicle Signing Information

The goal of this study was to examine the in-vehicle signing (IVS) function displayed on a mobile device to determine whether drivers’ compliance with speed limits increased when IVS information was present. The study also sought to identify whether any visual distraction occurred while the IVS information was being used. Notifications of speed zone changes along a roadway, of school zones, construction zones, and curves were visually displayed on a mobile device as per project requirements. Sixty participants (balanced for gender) completed the study, which involved performing a simulated drive in one of three conditions along 24 mi of roadways. The three system-on groups represented the following information conditions: IVS plus navigation, navigation only, or IVS only. Each group also completed a baseline (system-off) condition. The driving performance results indicated that drivers complied with most speed zones whether IVS information was present or not; however, average speeds tended to be higher in the system-on conditions. Drivers in the IVS-only condition spent significantly less time looking at the in-vehicle display than drivers who were also presented with navigation information. Response time to a roadside visual detection task was significantly increased only in speed transition zones whether IVS information was present or not. This condition suggests that increased driver workload occurs during transitions to a new speed zone, particularly when drivers are required to search the environment for additional visual information (e.g., signs, pedestrians, other vehicles).

Luminance Control of In-vehicle Display Based on Visual Field Driving Environment

Luminance Control of In-vehicle Display Based on Visual Field Driving Environment

User’s Satisfaction Analysis on the User-Oriented Public Transit Service in Busan

The User-Oriented Public Transit Service provide public transit service through media devices, such as mobile, BIT and display devices, which considered user`s individual characteristics and specific preference anytime and anywhere. The objective of this study is to develop and improve the services in the three media devices. This study applied user-satisfaction analysis in evaluating the service in Busan, analyze factor affecting the level of service user`s satisfaction, and draw remedies based on the analysis results. The user`s satisfaction average values in each media are 3.29 mobile, 3.62 BIT, and 4.05 display devices. Overall satisfaction average value 3.54 on the service showed a positive reaction from the survey participants. The important factor affected on general satisfaction of the User-Oriented Public Transit Service is In-vehicle display devices scored .632 (standardized coefficient) by categorical regression analysis. But users prefer to further improve the service environment rather than to add service information because they are already contented with the information they are getting. Furthermore, this study suggested ways of improving the User-Oriented Public Transit Service based on the satisfaction analysis results from the user`s perspective.

Improving In-Vehicle Display and Control Design for Older Drivers

Recommendations for older driver-friendly automobile interior design have been determined by taking into account older people's physical and cognitive characteristics. Twenty three older people (aged from 54 to 78) and five younger people (from 20 to 29) performed several tasks in actual driving conditions, in which their reaction times and performance errors were recorded. Some design factors were found to be related to older drivers' visibility and controllability. Several design recommendations were proposed in terms of cluster color and font, display location, and HVAC control type. Proposed recommendations are expected to satisfy a wider range of older drivers as these will facilitate automobile interior designs which are fitter to older drivers' visual, cognitive, and manual capabilities.

How fleeting emotions affect hazard perception and steering while driving: The impact of image arousal and valence

Video-billboards and portable video-display devices are becoming increasingly common and the images they project can often be dramatic or provocative. This study investigated the lingering effects of emotion-evoking images on driving as measured in a driving simulator. Images were projected on an in-vehicle display while drivers followed a lead vehicle at a safe distance. To ensure attention to the images drivers were required to indicate whether each image was positive or negative by pressing a button. Occasional braking events (sudden decelerations in the lead vehicle that necessitated braking) occurred either 250 or 500ms after the button press. In the 250ms delay condition braking RT was faster after high arousal images (fastest for high arousal positive images); following a 500ms delay braking RT was slower after high arousal images (slowest for high arousal negative images). Responding to all images reduced steering performance (in the period after the image but before the button press) but image valence had an effect on steering as well. Positive images were associated with better steering performance than negative images, especially when they were both low in arousal: a result that supports the broaden-and-build hypothesis of positive emotions and the theory that ambient (wide field/peripheral) vision controls steering performance. We discuss implications for both basic research on attention–emotion and applied research on driving.

A Binary Response Method to Determine the Usability of Seven In-Vehicle Fuel Economy Displays

We employed a binary response method to evaluate the usability of seven fuel economy displays. The displays were set to show various levels of fuel economy and then static images of the displays were generated. Participants were presented the images and asked to indicate if the information on the fuel economy display indicated fuel economy was greater or less than an arbitrary average fuel economy. A display that consisted of a binary metric of fuel economy and an incremental metric of acceleration best facilitated the determination of fuel economy.

A study on driver’s workload of telematics using a driving simulator: A comparison among information modalities

Recently, diffusion of telematics services and an explosive increase of in-vehicle display devices, such as Car Navigation Systems (CNSs), are becoming the new causes of traffic accidents. This is due to ‘inattention’ caused by an increase in the driver’s mental workload while he/she is driving. This situation has lead many countries to consider controlling the use of in-vehicle devices while driving through legislation. This research studies the effect of voice or display information systems on drivers through the Driver Eye Movement Analysis and the measurement of response ability. The experiment is carried out in a driving simulator and the results are presented through the comparative analysis of the driver’s visual field via the gaze tracking device and the average of correct answer rates for arithmetic problems.

In-vehicle data recorders for monitoring and feedback on drivers’ behavior

This paper describes the potential of in-vehicle data recorder (IVDR) systems to be used in various commercial and research applications as tools to monitor and provide feedback to drivers on their on-road behavior. The implementation of IVDR is demonstrated using the example of the DriveDiagnostics system. This system can identify various maneuver types that occur in the raw measurements, and use this information to calculate risk indices that indicate on the overall trip safety. Drivers receive feedback through various summary reports, real-time text messages or an in-vehicle display unit. Validation tests with the system demonstrate promising potential as a measurement tool to evaluate driving behavior. Reductions in crash rates and the risk indices are observed in the short-term.

In-Vehicle Glance Duration

In general, the unsafe conditions that are likely to produce a motor vehicle crash reside not at the mean of a given distribution (in other words, under typical conditions), but rather in the tails of the distribution. For example, an unusually slow response to a traffic obstacle, rather than an average response, may result in a collision. Although that situation means that crashes are the exception and not the norm, it has implications for how safety-critical data are approached and handled. In this current paper, experimental data collected in a driving simulator are used to demonstrate how an analysis of the average glance durations to an in-vehicle display might lead to different conclusions about safety compared with an alternative analysis of the tail end of the distribution. In addition, a model of crash risk based on the distribution of in-vehicle glances is described, as well as several characteristics of the traffic environment.

Safety implications of providing real-time feedback to distracted drivers

A driving simulator study was conducted to assess whether real-time feedback on a driver's state can influence the driver's interaction with in-vehicle information systems (IVIS). Previous studies have shown that IVIS tasks can undermine driver safety by increasing driver distraction. Thus, mitigating driver distraction using a feedback mechanism appears promising. This study was designed to test real-time feedback that alerts drivers based on their off-road eye glances. Feedback was displayed in two display locations (vehicle-centered, and IVIS-centered) to 16 young and 13 middle-aged drivers. Distraction was observed as problematic for both age groups with delayed responses to a lead vehicle-braking event as indicated by delayed accelerator releases. Significant benefits were not observed for braking and steering behavior for this experiment, but there was a significant change in drivers’ interaction with IVIS. When given feedback on their distracted state, drivers looked at the in-vehicle display less frequently regardless of where feedback was displayed in the vehicle. This indicates that real-time feedback based on the driver state can positively alter driver's engagement in distracting activities, helping them attend better to the roadway.

Dynamic Display of in-Vehicle Text Messages: The Impact of Varying Line Length and Scrolling Rate

This study examined the effect of varying dynamic display characteristics of in-vehicle text messages on visual sampling behavior. Sixteen participants navigated a simulated driving environment while reading text messages on an in-vehicle display. Each participant was exposed to four combinations of message segment length (short or long) and scrolling rate (slow or fast). Visual sampling was measured by the frequency and duration of glances to the display and the roadway, and comprehension of messages was measured by a series of post-drive questions. Results showed that varying segment length and scrolling rate affected the number of glances made to the display, but not their duration. Participants adjusted their reading rate to accommodate the rate at which messages scrolled, which protected reading comprehension but reduced the time spent viewing the roadway as the rate increased.

Presence and Quality of Navigational Landmarks: Effect on Driver Performance and Implications for Design

The objective of this study was to investigate the impact of landmark information of varying quality within drivers' navigation instructions on driving and navigation performance when navigating an unfamiliar route. Current vehicle navigation systems predominantly use distance-to-turn information to enable a driver to locate a forthcoming maneuver. Although it has been proposed that the design of driver navigation aids can be improved through the incorporation of landmarks as key navigation cues, little research has investigated how the quality of the landmark affects driver behavior. An empirical field trial in a real traffic environment was undertaken with 48 participants in order to assess the effect of landmark quality on driver behavior when navigating an unfamiliar, complex, urban route. The use of good landmarks (as opposed to poor landmarks or distance information) as key verbal navigation cues resulted in significant improvements in navigation performance, driving performance, and driver confidence immediately preceding a turn. The use of distance information to locate a turn resulted in significantly more glances to the in-vehicle display. Good landmarks offer significant safety and performance benefits to a driver navigating an unfamiliar route. Poor landmarks can result in driver performance worse than that obtained using distance to turn to locate forthcoming maneuvers. The design of future vehicle navigation systems should not rely on distance-to turn information alone to enable a driver to locate forthcoming maneuvers but, rather, should incorporate good landmarks within the navigation instructions they present to drivers.