Technical Session 6 Summaries
Please note: Some summaries have been edited for space and clarity. The conference proceedings will contain complete abstracts and papers.
(1) Determinants of Driving After Stroke Abiodun Emmanuel Akinwuntan, Hilde Feys, Willy De Weerdt, Jan Pauwels (Katholieke Universiteit Leuven ; Belgium), Guido Baten, Emmanuel Strypstein (CARA, Belgian Institute for Road Safety ; Belgium), Outstanding Student Paper Award Winner
Objective: To identify from a predriving assessment the tests that best predict the driving ability of stroke patients. Design: Examination of records of 104 first ever stroke patients who visited the Belgian Institute for Road Safety in 1998 and 1999 and performed the medical, visual, perceptual and the ‘on the road’ assessments. Measures: Variables such as age, sex, side of lesion, driving experience, visual tests, neuropsychological assessments most of which are from the Test for Attentional Performance (TAP) battery and an ‘on the road’ test were considered. Based on performances of subjects on the tests, a suitable, not immediately suitable or not suitable to drive decision was jointly taken by the team of assessors. Results: Following a logistic regression analysis, a combination of side of lesion, kinetic vision, visual scanning and the ‘on the road’ tests led to the best model in predicting the final group decision (R2=0.53). The ‘on the road’ test was the most important determinant (R2=0.42). Conclusion: The predictive accuracy of the decision is moderate. Inclusion of assessments more closely related to real road situations should be considered.
(2) Dynamic Evaluation of the Useful Field of View in Driving Daniel R. Mestre (Cognitive Neurosciences Centre, Centre National de la Recherche Scientifique ; France)
The concept of "useful field of view " (UFOV) was introduced to describe the area from which useful visual information can be extracted in a single glance. It is not restricted to the fovea, nor does it involve the entire visual field. It is often claimed that the UFOV decreases with age, with increasing speed of travel, or under the influence of drugs or stress. However, this potentially important tool for evaluating the role of human sensorial factors in road safety suffers from a lack of measurement techniques. Within this framework, we evaluated the ability of subjects to discriminate variations in their direction of heading from optical flow patterns simulating self-motion relative to a simple toric surface (a curved "tunnel"). We systematically evaluated perceptual performance as a function of the part of the global optical flow observers were looking at. Inasmuch as experimental laboratory data can be generalized to the complex task of driving, the results suggest that the perception of heading is optimal in a limited part of the visual field, that area which is situated close to the future direction of travel. The results offer a novel approach to the concept of useful field of view. They can be discussed in terms of their implications for road infrastructure design and for the positioning of warning and traffic signs within the driver's dynamic visual environment.
(3) Time-to-Contact and Collision-Detection Estimations as Measures of Driving Safety in Old and Dementia Drivers Nicoleta L. Read (University of Leeds ; UK), Nicholas J. Ward (University of Minnesota ; USA), Andrew M. Parkes (TRL Limited (Transport Research Laboratory) ; UK)
The paper discusses the importance of Time-to-Contact (TTC) and collision detection (CD) estimations for safe driving. It describes a computerised testing tool that requires TTC and CD estimations while dividing attention, and discusses the association between performance on this task and several measures of driving safety. We report four studies showing that the task is sensitive to age effects and dementia effects and that the accuracy of Time-to-Contact estimations differentiates between old and dementia drivers recently involved in accidents and those not involved. We also found an association between performance on this task and on navigation and car-following tasks in a driving simulator.
(4) Recent European Projects on Driver Impairment Nicholas J. Ward (University of Minnesota ; USA), Karel Brookhuis (University of Groningen ; The Netherlands)
It is estimated that at least 30% of all serious car accidents in Europe may be attributed to problems with the driver's state due to factors such as alcohol or drug use, fatigue, or health problems. This paper gives an overview of recent European Union projects to address this issue by assessing driver impairment. Whereas previous research has focused on vehicle technology (DREAM, DETER), or Human Machine Interfacing (SAVE, AWAKE), more recent efforts have been based on methods to detect the presence of substances (ROSITA) or the level of impaired performance at the roadside (CERTIFIED, IMMORTAL). This paper summarizes the objectives and main conclusions of the most recent research in this area.
(5) An Analysis of Driving Performance Measures Used to Assess the Effects of Medications on Drowsiness, Sedation and Driving Impairment Ginger Watson, John M. Weiler, George G. Woodworth, Julie Qidwai, Susan Quinn (University of Iowa ; USA)
The objective of this paper was to discuss the ability of driving scenarios and associated driving performance measures to demonstrate drowsiness, sedation, and driving impairment. The basis of this paper was a study that utilized a randomized, double-blind, double-dummy, four-treatment, four-period crossover trial in the Iowa Driving Simulator (IDS). Participants were 40 licensed drivers with seasonal allergic rhinitis who were 25 to 44 years of age. Treatments were Fexofenadine, diphenhydramine, alcohol, or placebo, given at weekly intervals before participants drove for 1 hour in the IDS. Measures examined included coherence, amplitude, phase angle, RMS error, following distance and behavior, lane keeping, response to unexpected vehicle intrusion and drowsiness. Study results show that sedating antihistamines impair driving performance as seriously as alcohol. Statistically significant but small correlations were found between subjective drowsiness and minimum following distance, steering instability, and left-lane excursions, although no correlation was greater than 0.21. Drowsiness was a weak predictor of driving impairment. This paper discusses these and other findings with an emphasis on the adequacy of driving scenarios and the sensitivity of the driving performance measures analyzed.
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