1.
Sandberg, David, 1980, et al.
(författare)
The impact of sleepiness on lane positioning in truck driving
2013. - 1
Ingår i: Driver Distraction and Inattention. - Farnham : Ashgate. - 9781409425854 - 9781315578156 ; , s. 405-416, s. 405-416
Bokkapitel (refereegranskat) abstract
This chapter concerns the detection of sleepiness in truck drivers. Data obtained from a driver sleepiness study involving real-world driving are used in order to analyse the performance of several sleepiness indicators based on driving behavior; such as, for example, variability in lateral position and heading angle. Contrary to the results obtained for passenger cars, for heavy trucks it is found that indicators based on variability provide little or no information; their performance does not rise significantly above chance levels.However, the data indicate that there is a significant difference in the average lane position for sleepy and alert drivers, respectively, such that a sleepy driver generally places the vehicle closer (by about 0.2 m) to the centre of the road than an alert driver. The analysis also shows a significant, monotonous, increase in average lateral position (measured from the right, outer, lane boundary towards the lane centre) between the four cases of (i) daytime alert driving, (ii) daytime sleepy driving, (iii) night-time alert driving and (iv) nighttime sleepy driving.
2.
Hallvig, D., et al.
(författare)
Sleepy driving on the real road and in the simulator - A comparison
2013
Ingår i: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575 .- 1879-2057. ; 50, s. 44-50
Tidskriftsartikel (refereegranskat) abstract
Sleepiness has been identified as one of the most important factors contributing to road crashes. However, almost all work on the detailed changes in behavior and physiology leading up to sleep related crashes has been carried out in driving simulators. It is not clear, however, to what extent simulator results can be generalized to real driving. This study compared real driving with driving in a high fidelity, moving base, driving simulator with respect to driving performance, sleep related physiology (using electroencephalography and electrooculography) and subjective sleepiness during night and day driving for 10 participants. The real road was emulated in the simulator. The results show that the simulator was associated with higher levels of subjective and physiological sleepiness than real driving. However, both for real and simulated driving, the response to night driving appears to be rather similar for subjective sleepiness and sleep physiology. Lateral variability was more responsive to night driving in the simulator, while real driving at night involved a movement to the left in the lane and a reduction of speed, both of which effects were absent in the simulator. It was concluded that the relative validity of simulators is acceptable for many variables, but that in absolute terms simulators cause higher sleepiness levels than real driving. Thus, generalizations from simulators to real driving must be made with great caution.
3.
Selander, Helena, 1975-, et al.
(författare)
Older drivers: On-road and off-road test results
2011
Ingår i: Accident Analysis and Prevention. - : Elsevier Science B.V., Amsterdam.. - 0001-4575 .- 1879-2057. ; 43:4, s. 1348-1354
Tidskriftsartikel (refereegranskat) abstract
Eighty-five volunteer drivers, 65-85 years old, without cognitive impairments impacting on their driving were examined, in order to investigate driving errors characteristic for older drivers. In addition, any relationships between cognitive off-road and on-road tests results, the latter being the gold standard, were identified. Performance measurements included Trail Making Test (TMT), Nordic Stroke Driver Screening Assessment (NorSDSA), Useful Field of View (UFOV), self-rating driving performance and the two on-road protocols P-Drive and ROA. Some of the older drivers displayed questionable driving behaviour. In total, 21% of the participants failed the on-road assessment. Some of the specific errors were more serious than others. The most common driving errors embraced speed: exceeding the speed limit or not controlling the speed. Correlations with the P-Drive protocol were established for NorSDSA total score (weak), UFOV subtest 2 (weak), and UFOV subtest 3 (moderate). Correlations with the ROA protocol were established for UFOV subtest 2 (weak) and UFOV subtest 3 (weak). P-Drive and self ratings correlated weakly, whereas no correlation between self ratings and the ROA protocol was found. The results suggest that specific problems or errors seen in an older persons driving can actually be "normal driving behaviours".
4.
Filtness, Ashleigh J, et al.
(författare)
Sleep-related eye symptoms and their potential for identifying driver sleepiness
2014
Ingår i: Journal of Sleep Research. - : Wiley. - 0962-1105 .- 1365-2869. ; 23:5, s. 568-75
Tidskriftsartikel (refereegranskat) abstract
The majority of individuals appear to have insight into their own sleepiness, but there is some evidence that this does not hold true for all, for example treated patients with obstructive sleep apnea. Identification of sleep-related symptoms may help drivers determine their sleepiness, eye symptoms in particular show promise. Sixteen participants completed four motorway drives on two separate occasions. Drives were completed during daytime and night-time in both a driving simulator and on the real road.Ten eye symptoms were rated at the end of each drive, and compared with driving performance and subjective and objective sleep metrics recorded during driving. 'Eye strain', 'difficulty focusing', 'heavy eyelids' and 'difficulty keeping the eyes open' were identified as the four key sleep-related eye symptoms. Drives resulting in these eye symptoms were more likely to have high subjective sleepiness and more line crossings than drives where similar eye discomfort was not reported. Furthermore, drivers having unintentional line crossings were likely to have 'heavy eyelids' and 'difficulty keeping the eyes open'. Results suggest that drivers struggling to identify sleepiness could be assisted with the advice 'stop driving if you feel sleepy and/or have heavy eyelids or difficulty keeping your eyes open'.
5.
Sandberg, David, 1980, et al.
(författare)
The Characteristics of Sleepiness During Real Driving at Night - A Study of Driving Performance, Physiology and Subjective Experience
2011
Ingår i: Sleep. - 1550-9109 .- 0161-8105. ; 34:10, s. 1317-1325
Tidskriftsartikel (refereegranskat) abstract
Study Objectives: Most studies of sleepy driving have been carried out in driving simulators. A few studies of real driving are available, but these have used only a few sleepiness indicators. The purpose of the present study was to characterize sleepiness in several indicators during real driving at night, compared with daytime driving. Design: Participants drove 55 km (at 90km/h) on a 9-m-wide rural highway in southern Sweden. Daytime driving started at 09: 00 or 11: 00 (2 groups) and night driving at 01: 00 or 03: 00 (balanced design). Setting: Instrumented car on a real road in normal traffic. Participants: Eighteen participants drawn from the local driving license register. Interventions: Daytime and nighttime drives. Measurement and Results: The vehicle was an instrumented car with video monitoring of the edge of the road and recording of the lateral position and speed. Electroencephalography and electrooculography were recorded, together with ratings of sleepiness every 5 minutes. Pronounced effects of night driving were seen for subjective sleepiness, electroencephalographic indicators of sleepiness, blink duration, and speed. Also, time on task showed significant effects for subjective sleepiness, blink duration, lane position, and speed. Sleepiness was highest toward the end of the nighttime drive. Night driving caused a leftward shift in lateral position and a reduction of speed. The latter two findings, as well as the overall pattern of sleepiness indicators, provide new insights into the effects of night driving. Conclusion: Night driving is associated with high levels of subjective, electrophysiologic, and behavioral sleepiness.
6.
Bianchi Piccinini, Giulio, 1982, et al.
(författare)
How Do Drivers Respond to Silent Automation Failures? Driving Simulator Study and Comparison of Computational Driver Braking Models
2020
Ingår i: Human Factors. - Chalmers University of Technology, Gothenburg, Sweden.; Volvo Group Trucks Technology, Gothenburg, Sweden.; Virginia Tech Transportation Institute, Blacksburg, USA.; University of Leeds, UK.; VTI, Gothenburg, Sweden. : SAGE Publications. - 1547-8181 .- 0018-7208. ; 62:7, s. 1212-1229
Tidskriftsartikel (refereegranskat) abstract
Objective: This paper aims to describe and test novel computational driver models, predicting drivers’ brake reaction times (BRTs) to different levels of lead vehicle braking, during driving with cruise control (CC) and during silent failures of adaptive cruise control (ACC). Background: Validated computational models predicting BRTs to silent failures of automation are lacking but are important for assessing the safety benefits of automated driving. Method: Two alternative models of driver response to silent ACC failures are proposed: a looming prediction model, assuming that drivers embody a generative model of ACC, and a lower gain model, assuming that drivers’ arousal decreases due to monitoring of the automated system. Predictions of BRTs issued by the models were tested using a driving simulator study. Results: The driving simulator study confirmed the predictions of the models: (a) BRTs were significantly shorter with an increase in kinematic criticality, both during driving with CC and during driving with ACC; (b) BRTs were significantly delayed when driving with ACC compared with driving with CC. However, the predicted BRTs were longer than the ones observed, entailing a fitting of the models to the data from the study. Conclusion: Both the looming prediction model and the lower gain model predict well the BRTs for the ACC driving condition. However, the looming prediction model has the advantage of being able to predict average BRTs using the exact same parameters as the model fitted to the CC driving data. Application: Knowledge resulting from this research can be helpful for assessing the safety benefits of automated driving.
7.
Thorslund, Birgitta, 1976-, et al.
(författare)
The influence of hearing loss on transport safety and mobility
2013
Ingår i: European Transport Research Review. - : Springer. - 1867-0717 .- 1866-8887. ; 5:3, s. 117-127
Tidskriftsartikel (refereegranskat) abstract
Purpose: To examine how road users with different degree of hearing loss experience safety and mobility in transport situations, compared to road users with normal hearing.Methods: A questionnaire study was conducted with participants recruited from the local branch of The Swedish hard of hearing society. A normal hearing control group, matched on age, gender and geographical location, was selected from a commercial database. The response rate was 35% (n = 194) in the group with Hearing Loss (HL) and 42% (n = 125) in the group with Normal Hearing (NH). The individuals with hearing loss were grouped into four groups according to the degree of their hearing loss (mild, moderate, severe and profound).Results: Hearing loss affected some specific aspects regarding transport situations, while others remained unaffected. Individuals with hearing loss were not as likely to have a driving license, but for those who have, hearing loss had no effect on mileage per year. Loss of hearing had an effect on criteria for choosing mode of transportation, but in the aggregate, no difference between the groups could be shown in the distribution of how much each mode of transportation was used. With a few exceptions, hearing loss did not affect the ratings of importance of hearing for different transportation modes. Hearing loss affected most questions regarding hearing and driver abilities, while avoidance of specific traffic situations was not associated with hearing loss. Hearing loss had only minor effects on the factors causing inattention when driving, and on the interest in a warning system for driver inattention. The interest in a warning system for driver inattention was high regardless of hearing category.Conclusions: Hearing loss influences the prevalence of driving license and criteria for choosing mode of transportation, however has no effect on the distribution of how much each mode of transportation was used. In general, in this study, respondents with higher degree of hearing loss were less concerned about the effect of hearing loss, indicating that they might be using coping strategies. The interest in warning system for inattention and the attitude towards strengthening of auditory information in traffic situations is high regardless of hearing category. This suggests further research on coping strategies and on design of support systems accessible for drivers with hearing loss.
8.
Thorslund, Birgitta, 1976-, et al.
(författare)
Vision measurability and its impact on safe driving : a literature review
2016
Ingår i: Scandinavian Journal of Optometry and Visual Science. - Linköping : Statens väg- och transportforskningsinstitut. - 1891-0882 .- 1891-0890. ; 9:1, s. 1-9
Tidskriftsartikel (refereegranskat) abstract
Knowledge of measurability of vision and its impact on safe driving have been proven to be important to secure a safe traffic system. Several different approaches to measuring visual function in order to improve road safety have been identified around the world. A trend seen in the literature is that traditional vision tests are increasingly supplemented by cognitive tests.The purpose of this study was to provide an overview of visual capabilities that are important for safe driving. The study answered questions about the visual capabilities that are essential for safe driving; which tests are available and how they are used; and existing evidence for these tests.The literature review was based on database searches of TRID, Web of Science and PubMed. In total 128 scientific publications were included in the overview. The results provided an overview of international standards of vision required for driving a car. Moreover, the results were structured according to the different visual capabilities and a corresponding account of the diseases that may affect these capabilities; available tests and corroborating evidence for the test; and the manner in which these capabilities are important for safe driving. Two tests were highlighted based on the review: contrast sensitivity, and Useful Field of View.It was also concluded that 1) testing of vision should consist of several complementary tests, 2) good visual acuity is not alone sufficient for safe driving, and 3) tests including cognitive aspects can complement vision testing and improve the assessment of safe driving.
9.
Vadeby, Anna, et al.
(författare)
Sleepiness and prediction of driver impairment in simulator studies using a Cox proportional hazard approach
2010
Ingår i: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575 .- 1879-2057. ; 42:3, s. 835-41
Tidskriftsartikel (refereegranskat) abstract
Cox proportional hazard models were used to study relationships between the event that a driver is leaving the lane caused by sleepiness and different indicators of sleepiness. In order to elucidate different indicators' performance, five different models developed by Cox proportional hazard on a data set from a simulator study were used. The models consisted of physiological indicators and indicators from driving data both as stand alone and in combination. The different models were compared on two different data sets by means of sensitivity and specificity and the models' ability to predict lane departure was studied.In conclusion, a combination of blink indicators based on the ratio between blink amplitude and peak closing velocity of eyelid (A/PCV) (or blink amplitude and peak opening velocity of eyelid (A/POV)), standard deviation of lateral position and standard deviation of lateral acceleration relative road (ddy) was the most sensitive approach with sensitivity 0.80. This is also supported by the fact that driving data only shows the impairment of driving performance while blink data have a closer relation to sleepiness. Thus, an effective sleepiness warning system may be based on a combination of lane variability measures and variables related to eye movements (particularly slow eye closure) in order to have both high sensitivity (many correct warnings) and acceptable specificity (few false alarms).
10.
Åkerstedt, Torbjörn, et al.
(författare)
Reaction of sleepiness indicators to partial sleep deprivation, time of day and time on task in a driving simulator - the DROWSI project
2010
Ingår i: Journal of Sleep Research. - : Wiley. - 1365-2869 .- 0962-1105. ; 19:2, s. 298-309
Tidskriftsartikel (refereegranskat) abstract
Studies of driving and sleepiness indicators have mainly focused on prior sleep reduction. The present study sought to identify sleepiness indicators responsive to several potential regulators of sleepiness: sleep loss, time of day (TOD) and time on task (TOT) during simulator driving. Thirteen subjects drove a high-fidelity moving base simulator in six 1-h sessions across a 24-h period, after normal sleep duration (8 h) and after partial sleep deprivation (PSD; 4 h). The results showed clear main effects of TOD (night) and TOT but not for PSD, although the latter strongly interacted with TOD. The most sensitive variable was subjective sleepiness, the standard deviation of lateral position (SDLAT) and measures of eye closure [duration, speed (slow), amplitude (low)]. Measures of electroencephalography and line crossings (LCs) showed only modest responses. For most variables individual differences vastly exceeded those of the fixed effects, except for subjective sleepiness and SDLAT. In a multiple regression analysis, SDLAT, amplitude/peak eye-lid closing velocity and blink duration predicted subjective sleepiness bouts with a sensitivity and specificity of about 70%, but were mutually redundant. The prediction of LCs gave considerably weaker, but similar results. In summary, SDLAT and eye closure variables could be candidates for use in sleepiness-monitoring devices. However, individual differences are considerable and there is need for research on how to identify and predict individual differences in susceptibility to sleepiness.
