Valid representation of a highly dynamic collision avoidance scenario in a driving simulator

In Germany the second-most frequent accidents in road traffic are rear-end collisions. For this reason rear-end collisions are quite important for accident research and the development of driving safety systems. To examine the functionality and to design the human–machine-interface of new driving safety systems, especially in the early development phase, subject tests are necessary. Because of the great hazard potential of such safety critical scenarios for the test persons, they are often conducted in a driving simulator (DS). Accordingly, validity is an important qualification to ensure that the findings collected in a simulated test environment can be directly transferred to the real world.This paper regards the question of driving behavior validity of DS in critical situations. There are hardly any validation studies which analyze the driving behavior in a specific collision avoidance situation.The validation study described in this paper aims to evaluate the behavioral validity of a fixed-base simulator in a collision avoidance situation. For this reason a field study from 2007 was replicated in a fixed-base simulator environment.The main questions of this validation study were if the driver can notice an active hazard braking system and if the driving behavior in a static simulator can be valid in such a critical situation.The key finding of the study states that there is no driving behavior validity in a static driving simulator for the tested dynamic scenario. The missing vestibular feedback causes a different behavior of the participants in field and simulator. The resulting absence of comparability leads to non-valid performance indicators. But these indicators are key parameters for analyzing the function and acceptance of active braking systems. So the question arises, which motion performance does a motion base have to provide in order to achieve valid acceleration simulation of such a highly dynamic collision avoidance scenario. The DS’s performance is measured in workspace, velocity and acceleration.     

The behavioral validity of dual-task driving performance in fixed and moving base driving simulators

Next generation automotive hardware and user interfaces are increasingly pre-tested in driving simulators. What are the potential limitations of such simulations? We determined the relative and absolute validity of five different driving simulators at the Daimler AG by evaluating five functions of an in-vehicle system based on the guideline of the Alliance of Automobile Manufacturers (2006). The simulations were compared to on-road driving. We hypothesized that not only simulator characteristics, but also user characteristics, such as simulator sickness, gender, or age, influence behavioral validity. Even though relating simulator characteristics and user characteristics to driving performance across different driving simulators and driving tasks is difficult, our results are surprisingly in line with the current body of research. We demonstrate the usefulness of all simulators on a relative and partially on an absolute level with moving-base simulators being preferable to fixed-base simulators. As hypothesized, we showed that simulator sickness was significantly associated with impaired performance. In the fixed-base simulators, we found a significant interaction between age and gender, which we could not find in moving-base simulators and in the on-road study. Explanations for our findings and practical implications are discussed.     

The relationship between simulator sickness and driving performance in a high-fidelity simulator

Driving simulators are highly valuable tools for various applications such as research, training, and rehabilitation. However, they are also known to cause simulator sickness, a special form of traditional motion sickness. Common side effects of simulator sickness include nausea, headache, dizziness, eye-strain, and/or disorientation, all symptoms which may negatively impact driving performance. The goal of the present study was to investigate the relationship between simulator sickness and driving performance obtained in a high-fidelity driving simulator. Twenty-one healthy participants were engaged in a simulated driving task containing rural, city, and highway sections for approx. 25 min. Participants were asked to drive naturally while obeying traffic rules and completing common driving maneuvers (including reactions to sudden events). Driving performance was evaluated based on various driving measures, such as lane positioning, speed measures, following distance, or the number of steering reversals. Simulator sickness was measured before, during, and after the simulated drive using a combination of the Simulator Sickness Questionnaire and the Fast Motion Sickness scale. Overall, correlations between the level of simulator sickness and driving performance measures were low to moderate (r’s from -0.37 to 0.40) and were not significant. Additionally, participants who reported higher levels of simulator sickness did not differ with regards to their driving performance from those who reported lower simulator sickness scores. Our results suggest that the presence of simulator sickness is not strongly related to performance in a driving simulator.     

DEVELOPMENT OF A BEHAVIORALLY BASED PERFORMANCE APPRAISAL SYSTEM

This paper describes the development of a behaviorally based performance appraisal system. Blanz and Ghiselli's Mixed Standard Scale was used as the basis for developing the performance appraisal system for assessing the performance of highway patrol personnel. However, the particular developmental procedures described here differ in some respects from those reported in the literature. Rather than developing rating items describing general traits such as "diligence,""initiative," or "enthusiasm" in behavioral terms, the items in the present scale were developed to describe proficiency levels of specific job tasks. This characteristic is expected to enhance the objectivity of the evaluation system for both appraisal and job counseling purposes. The appraisal instrument was subjected to a series of reliability and validity tests that demonstrated its high reliability and validity. Although the content of the appraisal sytem desribed here included highway patrol tasks, a similar system could be developed using the procedures described for a wide variety and level of jobs.     

Exploring behavioral validity of driving simulator under time pressure driving conditions of professional drivers

Driving simulators have become an important tool in human factors research, given that they are appropriately validated. Therefore, this study aims to explore the behavioral (absolute and relative) validity of a fixed-base driving simulator by analyzing different driving behavior measures such as speed, longitudinal acceleration, lateral acceleration, and brake pedal force. Thirty professional drivers participated in the experiment and the data was collected in real and simulated worlds under No Time Pressure (NTP) and Time Pressure (TP) driving conditions. Initially, comparative analyses were conducted on different driving behavior measures using Wilcoxon-signed rank test to examine absolute validity of the driving simulator. Finally, Generalized Linear Mixed (GLM) models were developed for computing the effective distance between real and simulated worlds by quantifying the parameters and for establishing relative validity. In general, the continuous profiles of driving behavior measures followed similar trends in real and simulated worlds and comparative analyses indicated relative validity of the driving simulator. The GLM models showed significant interaction effect of driving environments (real-world and simulated world) and driving conditions (NTP and TP) where high driving speed, high brake pedal force, and low lateral acceleration were observed in simulated world under TP driving condition than real-world under TP driving condition. Overall, the statistical analyses showed qualitative correspondence (relative validity) of the driving behavior measures in between real and simulated worlds. The findings from the current study showed expediency of the driving simulator and its effectiveness in conducting research on human factors and driver safety.     

Diverging diamond interchanges: A driving simulator study

This study assessed driver performance while navigating a Diverging Diamond Interchange (DDI) compared to a standard intersection in a driving simulator. A total of 201 Western Australian (WA) drivers aged 18–80 years completed the simulator drive and questionnaire. Measures of driving simulator performance assessed included time spent out of lane, number of lane excursions, compliance to the speed limit, crashes and near misses. Other driving measures, which were recorded by the researcher, included driver errors/violations such as red-light violations, wrong way violations and navigation errors. Qualitative information was also obtained in a post exit interview with each participant regarding the difficulties they experienced when driving through the DDI. A repeated-measure analysis of variance (r-ANOVA) was undertaken to examine differences in intersection type (DDI versus standard intersection) and driving performance measures from the driving simulator. The only significant result was compliance to the speed limit (F (1, 656) = 160.11, p < 0.001) on the driving simulator. A higher proportion of red-light violations were observed by the researcher as participants navigated through the DDI, compared to the standard intersection. Qualitative comments from participants also highlighted the need for better signage and road markings. Recommendations when DDIs are implemented include community education on speed limit compliance, avoidance of red-light violations and design improvements regarding signage and road markings.     

On the relation between personality and job performance of airline pilots

The validity of a personality questionnaire for the prediction of job success of airline pilots is compared to validities of a simulator checkflight and of flying experience data. During selection, 274 pilots applying for employment with a European charter airline were examined with a multidimensional personality questionnaire (Temperature Structure Scales; TSS). Additionally, the applicants were graded in a simulator checkflight. On the basis of training records, the pilots were classified as performing at standard or below standard after about 3 years of employment in the hiring company. In a multiple-regression model, this dichotomous criterion for job success can be predicted with 73.8% accuracy through the simulator checkflight and flying experience prior to employment. By adding the personality questionnaire to the regression equation, the number of correct classifications increases to 79.3%. On average, successful pilots score substantially higher on interpersonal scales and lower on emotional scales of the TSS.     

Driving errors,estimated performance and individual characteristics under simulated and real road traffic conditions – A validation study

BackgroundThe suitability of driving simulators for the prediction of driving behaviour in road traffic has been able to be confirmed in respect of individual assessment parameters. However, there is a need for overarching approaches that take into account the interaction between various influencing factors in order to establish proof of validity. The aim of this study was to explore the validity of our driving simulator in respect of its ability to predict driving behaviour based on participants‘ observed driving errors and driver’s individual characteristics.Method41 healthy participants were assessed both in a Smart-Realo-Simulator and on the road. By means of linear modelling, the correlation between observed driving errors was investigated. In addition, the influence of self-reported and externally assessed driving behaviour as well as individual parameters (education and training; driving history) were analysed.ResultsBy including these factors, 58% of the variance could be explained. For observed driving errors, a relative validity was established. For self-reported and externally assessed driving behaviour, an absolute to relative validity emerged. The amount of time spent in education and training proved to have a significant influence on driving performance in the simulator, but not on the road.DiscussionIn general, our results confirmed the validity of our driving simulator with regard to observed and self-reported driving behaviour. It emerged that education and training as potential indicators of cognitive resources played a differential role regarding the study conditions. Since real road driving is considerably automated in experienced drivers, this result suggests that simulation-related behavioural regulation is challenged by additional cognitive demands as opposed to behavioural regulation extending to real road driving. However, the source of these additional cognitive demands remains currently elusive and may form the subject of future research.     

Head-mounted displays for clinical virtual reality applications: pitfalls in understanding user behavior while using technology.

The use of virtual environments with head-mounted displays (HMDs) offers unique assets to the evaluation and therapy of clinical populations. However, research examining the effects of this technology on clinical populations is sparse. Understanding how wearers interact with the HMD is vital. Discomfort leads to altered use of the HMD that could confound performance measures; the very measures which might be used as tools for clinical decision making. The current study is a post-hoc analysis of the relationship between HMD use and HMD comfort. The analysis was conducted to examine contributing factors for a high incidence of simulator sickness observed in an HMD-based driving simulator. Pearson correlation analysis was used to evaluate objective and subjective measures of HMD performance and self-reported user comfort ratings. The results indicated weak correlations between these variables, indicating the complexity of quantifying user discomfort and HMD performance. Comparison of two case studies detailing user behavior in the virtual environment demonstrates that selected variables may not capture how individuals use the HMD. The validity and usefulness of the HMD-based virtual environments must be understood to fully reap the benefits of virtual reality (VR) in rehabilitation medicine.     

Specific Aptitude Theory Revisited: Is There Incremental Validity for Training Performance?

There has been controversy over the years about whether specific mental abilities increment validity for predicting performance above and beyond the validity for general mental ability (GMA). Despite its appeal, specific aptitude theory has received only sporadic empirical support. Using more exact statistical and measurement methods and a larger data set than previous studies, this study provides further evidence that specific aptitude theory is not tenable with regard to training performance. Across 10 jobs, differential weighting of specific aptitudes and specific aptitude tests were found not to improve the prediction of training performance over the validity of GMA. Implications of this finding for training research and practice are discussed.     

A validation study of driving errors using a driving simulator

BackgroundDriving simulators have become an important research tool in road safety. They provide a safer environment to test driving performance and have the capacity to manipulate and control situations that are not possible on-road.AimTo validate a laboratory-based driving simulator in measuring on-road driving performance by type and mean driving errors.MethodsParticipants were instructed to drive a selected route on-road. The same route was programmed in the driving simulator using the UC/Win-road software. All participants completed a background questionnaire. On-road driving behaviours of participants and driving behaviours in the simulator were assessed by an occupational therapist and two trained researchers using an assessment form. Interclass correlations were calculated to assess the inter-rater agreement between the researchers on driving behaviours. Paired t-tests were used to assess differences in driving performance between the simulator and on-road assessments.ResultsA convenience sample of 47 drivers aged 18–69 years who held a current Western Australian class C licence (passenger vehicle) were recruited into the study. The mean age was 34.80 years (SD: 13.21) with twenty-six males (55.32%) and 21 females (44.68%) completing the study. There was no statistical difference between the on-road assessment and the driving simulator for mirror checking, left, right and forward observations, speed at intersections, maintaining speed, obeying traffic lights and stop signs.ConclusionThe preliminary results provide early support for the relative validity of the driving simulator which may be used for a variety of road safety outcomes with reduced risk of harm to participants.     

The validity of the Big Five personality traits for job performance: Meta‐analyses of South African studies

Previous meta‐analyses have established the Big Five personality traits as important predictors of job performance around the globe. This study extends the international generalizability of Big Five criterion‐related validity through systematic review and meta‐analyses of personality–performance research conducted in South Africa. We meta‐analyzed data from 33 studies and 6,782 individuals to estimate validities of Big Five traits for various job performance criteria. Results showed that the Big Five traits have similar validity for job performance criteria as found in other cultural contexts. Conscientiousness was the strongest predictor across performance criteria, while other traits showed validity for specific criteria or subsamples. Results demonstrate the importance of psychometric meta‐analysis for building cumulative knowledge and support applied use of personality assessments in South Africa. Consistency of the results of this study with those of previous meta‐analyses in other national contexts supports the argument that personality–performance relations are a cultural universal.     

Mapping drivers’ mental models of adaptive cruise control to performance

Driver support features (DSF) have the potential to improve safety, but they also change the driver-vehicle relationship —as well as their respective roles and responsibilities. To maximize safety, it is important to understand how drivers’ knowledge and understanding of these technologies—referred to as drivers’ mental models—impact performance and safety. This simulator study examined how drivers with different mental models of adaptive cruise control performed in edge cases. The study compared the responses of groups of drivers, with strong and weak mental models of ACC, established through a combination of screening, training, and exposure, in edge case situations in a high-fidelity driving simulator. In general, participants with strong mental models were faster than those with weak mental models to respond in edge-case situations—defined as cases where the ACC did not detect an approaching object, such as a slow-moving motorcycle. The performance deficits observed for drivers with weak mental models appear to reflect uncertainty surrounding how ACC will behave in edge cases.     

Keep calm,pay attention,and carry on: Anxiety and consciousness mediate the effect of,mindfulness on driving performance in young drivers

Road traffic crashes are currently one of the main causes of deaths in the world and many efforts have been made to develop effective interventions to reduce them. Mindfulness has risen as a method for improving mental and physical well-being and has been hypothesized as potentially beneficial for driving performance. This has led to some commercial ventures based on such hypothesis, despite that the empirical evidence backing up them is still limited. Besides, at the moment there is not yet a clear account of the specific mechanism underlying this proposals. So, it seems plausible that the relationship between mindfulness and driving performance is indirect, and that personality traits such as conscientiousness and neuroticism may play a mediation role between mindfulness and driving performance. A sample of 98 drivers between the ages of 19 and 29 completed questionnaires assessing mindfulness, anxiety trait and anxiety state, and the big five personality traits. Driving performance was assessed in a driving simulator. A mediation model was fitted with conscientiousness and neuroticism set as mediators of the effects of the relationship between the subject’s mindfulness levels and the driving performance.     

Analyzing driver's response to the yellow onset at signalized intersections

Intersections are critical points within the highway system at which the risk of crashes increases. This study seeks to better understand drivers’ behavior at an intersection by examining the relationship between their observed driving behavior, psychological attributes and decision to proceed through an intersection. A driving simulator and self-report questionnaire were used to understand driver decision-making at the onset of the yellow phase across several signalized intersections. The simulator measured driving outcomes such as speed, braking, and throttle as drivers cross through four increasingly difficult intersections. The questionnaires measured demographics, psychological traits including mindfulness and impulsiveness along with self-reported driving behaviors. A total of 102 participants completed the questionnaire as well as the driving simulator experiment. Hierarchical clustering served to classify drivers into four groups on the basis of their observed driving in the simulator: the safest drivers, safe drivers, speed demons, and aggressive drivers. These driving styles moderated the relationship between the drivers’ psychological traits and their decision to stop or proceed at each intersection. Results showed that mindfulness was highly related to the safest drivers’ decision to stop at the first intersection, while impulsiveness and anxiety were related to the speed demons’ decision to stop at the third intersection. These findings lay a strong foundation for developing progressive educational campaigns incorporating driver psychology in their methodology. Findings also provide support for research linking driving performance and psychological traits with implications for intersection design.     

Examining the validity of self‐reports on scales measuring students' strategic processing

Background. Self‐report inventories trying to measure strategic processing at a global level have been much used in both basic and applied research. However, the validity of global strategy scores is open to question because such inventories assess strategy perceptions outside the context of specific task performance. Aims. The primary aim was to examine the criterion‐related and construct validity of the global strategy data obtained with the Cross‐Curricular Competencies (CCC) scale. Additionally, we wanted to compare the validity of these data with the validity of data obtained with a task‐specific self‐report inventory focusing on the same types of strategies. Sample. The sample included 269 10th‐grade students from 12 different junior high schools. Methods. Global strategy use as assessed with the CCC was compared with task‐specific strategy use reported in three different reading situations. Moreover, relationships between scores on the CCC and scores on measures of text comprehension were examined and compared with relationships between scores on the task‐specific strategy measure and the same comprehension measures. Results. The comparison between the CCC strategy scores and the task‐specific strategy scores suggested only modest criterion‐related validity for the data obtained with the global strategy inventory. The CCC strategy scores were also not related to the text comprehension measures, indicating poor construct validity. In contrast, the task‐specific strategy scores were positively related to the comprehension measures, indicating good construct validity. Conclusion. Attempts to measure strategic processing at a global level seem to have limited validity and utility.     

Effects of visual and cognitive load in real and simulated motorway driving

As part of the HASTE European Project, effects of visual and cognitive demand on driving performance and driver state were systematically investigated by means of artificial, or surrogate, In-vehicle Information Systems (S-IVIS). The present paper reports results from simulated and real motorway driving. Data were collected in a fixed base simulator, a moving base simulator and an instrumented vehicle driven in real traffic. The data collected included speed, lane keeping performance, steering wheel movements, eye movements, physiological signals and self-reported driving performance. The results show that the effects of visual and cognitive load affect driving performance in qualitatively different ways. Visual demand led to reduced speed and increased lane keeping variation. By contrast, cognitive load did not affect speed and resulted in reduced lane keeping variation. Moreover, the cognitive load resulted in increased gaze concentration towards the road centre. Both S-IVIS had an effect on physiological signals and the drivers’ assessment of their own driving performance. The study also investigated differences between the three experimental settings (static simulator, moving base simulator and field). The results are discussed with respect to the development of a generic safety test regime for In-vehicle Information Systems.     

Influences of APOE ε4 and expertise on performance of older pilots

Little is known about how APOE ε4-related differences in cognitive performance translate to real-life performance, where training and experience may help to sustain performance. We investigated the influences of APOE ε4 status, expertise (FAA pilot proficiency ratings), and their interaction on longitudinal flight simulator performance. Over a 2-year period, 139 pilots aged 42-69 years were tested annually. APOE ε4 carriers had lower memory performance than noncarriers (p = .019). APOE interacted with Expertise (p = .036), such that the beneficial influence of expertise (p = .013) on longitudinal flight simulator performance was more pronounced for ε4 carriers. Results suggest that relevant training and activity may help sustain middle-aged and older adults' real-world performance, especially among APOE ε4 carriers.