New knowledge and methods for mitigating driver distraction

Driver distraction is the diversion of attention to a non-driving related activity. It has been identified as major cause of accidents. Even as we move away from traditional ‘driver’ and towards highly-automated vehicles, distraction remains an important issue. A distracted driver could still potentially miss a handover of control message from the car, or have a reduced awareness of the traffic environment. With the increased number and complexity of new features being introduced in vehicles, it is becoming more important to understand how drivers interact with them, to understand the benefit they offer in helping the driver to focus on-road, but also to identify their limitations and risks. Thereby it is important to consider that the interaction between human and technology, e.g. driver distraction, can be described by many aspects. To learn the most about the interaction between user and technology, it is important to select a suitable measure and to utilise that measure in best practice, which can be hard to find in literature. This research project is divided into two research streams that investigate the opportunities of new in-vehicle interfaces to mitigate driver distraction and that research how to efficiently identify measures for the ergonomic evaluation of in-vehicle interfaces. Research stream one, comprising four studies, evaluated tactile information as a new interface technology to mitigate distraction in manual and automated cars. Tactile perception requires physical contact between the driver and the device delivering the feedback. It can be decreased by clothing. In the first user trial it was evaluated, for the first time, how shoe type, gender, and age influence the driver’s perception of a tactile pedal. Shoe type did not, but gender, age, and the feedback’s duration and amplitude did influence the perception. In some durations and amplitudes, the feedback was recognised by all participants and was rated highly intense, both aspects a warning should have. Next, it was evaluated how fast people would react to a tactile warning compared to a traditional auditory warning and an auditory-tactile warning. The participants reacted significantly slower to the tactile warning. Following, a tactile warning might not be suitable as an in-vehicle warning. However, adding an auditory component to the tactile warning increases its efficiency and people missed less auditory-tactile compared to auditory warnings. Newly introduced interfaces, such as tactile interfaces, put an effort on drivers to adjust to them and might lead to unsafe interactions. In the third and fourth study, it was investigated how a driver’s trust effects the reaction time and glance behaviour. Trust was not associated with the reaction time towards a tactile warning signal, but it influenced the glances at a voice-navigation interface that was new for the majority of the participants. The findings can be utilised to increase the trust in the interface dialogue and thereby decrease a driver’s time glanced off-road. Research stream two investigated how Human-Machine-Interface (HMI) engineers can be supported in the comparison and selection of measures (e.g. a usability score) to evaluate the ergonomics of in-vehicle devices, for example to measure driver distraction. Industry projects are often restricted by tight deadlines and limited availability of equipment. Measure selection can then become a time critical issue. In published literature, there existed no guidelines to support this task. In four rapid prototyping evaluations, an interface was developed that can aid HMI-engineers in the comparison and selection of measures for an ergonomic evaluation. The tool functions as knowledge management and foresees to inform users about the best practice to utilise a measure, tips to set-up required equipment, and templates for the measure, for example templates for the analysis or electronic versions of questionnaires

Haptic foot pedal : influence of shoe type, age, and gender on subjective pulse perception

This study investigates the influence of shoe type (sneakers and safety boots), age, and gender on the perception of haptic pulse feedback provided by a prototype accelerator pedal in a running stationary vehicle. Haptic feedback can be a less distracting alternative to traditionally visual and auditory in-vehicle feedback. However, to be effective, the device delivering the haptic feedback needs to be in contact with the person. Factors such as shoe type vary naturally over the season and could render feedback that is perceived well in one situation, unnoticeable in another. In this study, we evaluate factors that can influence the subjective perception of haptic feedback in a stationary but running car: shoe type, age, and gender. Thirty-six drivers within three age groups (≤39, 40-59, and ≥60) took part. For each haptic feedback, participants rated intensity, urgency, and comfort via a questionnaire. The perception of the haptic feedback is significantly influenced by the interaction between the pulse's duration and force amplitude and the participant's age and gender but not shoe type. The results indicate that it is important to consider different age groups and gender in the evaluation of haptic feedback. Future research might also look into approaches to adapt haptic feedback to the individual driver's preferences. Findings from this study can be applied to the design of an accelerator pedal in a car, for example, for a nonvisual in-vehicle warning, but also to plan user studies with a haptic pedal in general

The comparison of auditory, tactile, and multimodal warnings for the effective communication of unexpected events during an automated driving scenario

In an automated car, users can fully engage in a distractor task, making it a primary task. Compared to manual driving, drivers can engage in tasks that are difficult to interrupt and of higher demand, the consequences can be a reduced perception of, and an impaired reaction to, warnings. In this study we compared three in-vehicle warnings (auditory, tactile, and auditory-tactile) which were presented during three highly attention capturing tasks (visual, auditory, and tactile) while the user was engaged in a self-driving car scenario, culminating in an emergency brake event where the warning was presented. The novel addition for this paper was that three set paced, attention capturing tasks, as well the three warnings were all designed in a pilot study to have comparable workload and noticeability. This enabled a direct comparison of human performance to be made between each of the attention capturing tasks, which are designed to occupy only one specific modality (auditory, visual or haptic), but remain similar in overall task demand. Results from the study showed reaction times to the tactile warning (for the emergency braking event) were significantly slower compared to the auditory and auditory-tactile (aka multimodal or multisensory) warning. Despite the similar reaction times between the in-vehicle auditory warning and the multimodal warning, the multimodal warning led to a reduced number of missed warnings and fewer false responses. However, the auditory and auditory-tactile warnings were rated significantly more startling than the tactile alone. Our results extend the literature regarding the performance benefits of multimodal warnings by comparing them with in-vehicle auditory warnings in an autonomous driving context. The set-pace attention capturing tasks in this study would be of interest to other researchers to evaluate the interaction in an automated driving context, particularly with hard to interrupt and attention capturing tasks

Research knows best, but how to communicate distraction measures practically in an industrial context

Selection and comparison of human-factors related measures for evaluations of in-vehicle devices involves weighting of multiple criteria. It may result in a complex decision-making process for the practitioner, specifically in a time pressured industrial context. Visual information seeking has successfully been applied to reduce the complexity of datasets in healthcare and other fields. Information is presented visually and divided in ‘Overview’, representing the data by its characteristic criteria, and ‘Details’, which are presented on demand. This division reduces information load for the user and eases comparison based on characteristics. This project, first, aims to understand what criteria practitioners use to decide about the suitability of a measure for an in-vehicle evaluation. Secondly, criteria practitioners use to select measures are implemented in a new interface approach based on methods of visual information seeking to support users in the selection and comparison of human-factors related measures for in-vehicle evaluations. Overall, the interface exposes practitioners to new measures, enables them to rapidly compare measures, and obtain information to practically apply the

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Good vibrations : driving with a haptic pedal

The study at hand evaluates if and how perception of haptic pulse feedback provided by an accelerator pedal in a stationary car differs dependent on the shoe type (herein safety boots and plimsolls) or the age and gender of the participant. Intermediate results indicate that the shoe type and age do not have a significant influence on the haptic perception. However, haptic perception seems to be significantly influenced by gender

A Link Between Trust in Technology and Glance Allocation in On-Road Driving

This paper examines whether there is an association between preexposure trust in technology and subsequent glance behavior when interacting with a technology that was relatively novel for the majority of participants. After rating their level of trust in technology on a questionnaire, participants drove one of two vehicle models on a highway and engaged in a voice-based navigation address entry task. Subjective ratings of trust in new car technologies were found to be significantly positively correlated with a higher frequency of glances across all coded glance regions during the task. In one of the voice-interface implementations, these higher ratings of trust were also associated with a higher frequency of glances to the user interface, but with fewer long duration (>2s) glances per minute. A lower trust in technology in general showed some association with taking more time to complete interactions. The findings are discussed as highlighting the potential value of further research into the associations between trust and visual scanning behavior

Clinical manifestations of intermediate allele carriers in Huntington disease

Objective: There is controversy about the clinical consequences of intermediate alleles (IAs) in Huntington disease (HD). The main objective of this study was to establish the clinical manifestations of IA carriers for a prospective, international, European HD registry. Methods: We assessed a cohort of participants at risk with <36 CAG repeats of the huntingtin (HTT) gene. Outcome measures were the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive, and behavior domains, Total Functional Capacity (TFC), and quality of life (Short Form-36 [SF-36]). This cohort was subdivided into IA carriers (27-35 CAG) and controls (<27 CAG) and younger vs older participants. IA carriers and controls were compared for sociodemographic, environmental, and outcome measures. We used regression analysis to estimate the association of age and CAG repeats on the UHDRS scores. Results: Of 12,190 participants, 657 (5.38%) with <36 CAG repeats were identified: 76 IA carriers (11.56%) and 581 controls (88.44%). After correcting for multiple comparisons, at baseline, we found no significant differences between IA carriers and controls for total UHDRS motor, SF-36, behavioral, cognitive, or TFC scores. However, older participants with IAs had higher chorea scores compared to controls (p 0.001). Linear regression analysis showed that aging was the most contributing factor to increased UHDRS motor scores (p 0.002). On the other hand, 1-year follow-up data analysis showed IA carriers had greater cognitive decline compared to controls (p 0.002). Conclusions: Although aging worsened the UHDRS scores independently of the genetic status, IAs might confer a late-onset abnormal motor and cognitive phenotype. These results might have important implications for genetic counseling. ClinicalTrials.gov identifier: NCT01590589