Makoto Kihira

Eye-Gaze Tracking Analysis of Driver Behavior While Interacting With Navigation Systems in an Urban Area

With the advent of global positioning system technology, smart phones are used as portable navigation systems. Guidelines that ensure driving safety while using conventional on-board navigation systems have already been published but do not extend to portable navigation systems; therefore, this study focused on the analysis of the eye-gaze tracking of drivers interacting with portable navigation systems in an urban area. Combinations of different display sizes and positions of portable navigation systems were adopted by 20 participants in a driving simulator experiment. An expectation maximum algorithm was proposed to classify the measured eye-gaze points; furthermore, three measures of glance frequency, glance time, and total glance time as a percentage were calculated. The results indicated that the convenient display position with a small visual angle can provide a significantly shorter glance time but a significantly higher glance frequency; however, the small-size display will bring on significantly longer glance time that may result in the increasing of visual distraction for drivers. The small-size portable display received significantly lower scores for subjective evaluation of acceptability and fatigue; moreover, the small-size portable display on the conventional built-in position received significantly lower subjective evaluation scores than that of the big-size one on the upper side of the dashboard. In addition, it indicated an increased risk of rear-end collision that the proportion of time that the time-to-collision was less than 1 s was significantly shorter for the portable navigation than that of traditional on-board one.

Factors contributing to driver choice after hitting a pedestrian in Japan

In Japan, where pedestrian deaths account for a third of road traffic fatalities, 7.4% of victims die from hit-and-run accidents. To identify determinants for drivers considering leaving an accident scene after hitting a pedestrian, environment-related, driver-related, and pedestrian-related factors were examined using Japanese national police data. Results generally confirmed the conceptual framework of previous studies, which examined hit-and-run behavior based on a classic economic cost-benefit approach. However, results suggest that effects of road-related factors and harsher legal punishments have limited influence for reducing hit-and-run likelihood after a driver hits a pedestrian. Measures to prevent hit-and-run accidents are presented herein.

Gaze measurement to evaluate safety in using vehicle navigation systems

It becomes popular to use smart phones as a car navigation system. Conventional navigation systems were already designed following the published guidelines to ensure driving safety; however, guidelines for the smart phone navigation system are still undeveloped. To assess the safety of these devices, the car navigation systems are integrated into a driving simulator. The experiments are carried out by changing the size and the position of the display. Gazing points of the drivers are measured when they are driving on the driving simulator following the instruction of the car navigation systems as well as obtaining questionnaires. The results indicate the frequency of eye movement increases when the display is installed close to the drivers eye, while total time gazing the display does not change significantly in all the conditions.

Typology of Driving-Under-The-Influence (DUI) Offenders Revisited: Inclusion of DUI-Specific Attitudes

OBJECTIVES Much work remains to improve rehabilitative interventions for driving-under-the-influence (DUI) offenders. There is heterogeneity of patterns of alcohol use, personality, and driving behaviour within DUI offenders, but little is known about how their appraisal of DUI differs. This study investigated within-offender variability in DUI-specific attitudinal variables. METHOD Convicted male DUI offenders (N=219) living in greater Tokyo were interviewed. Cluster analysis was undertaken using age, psychological distress, personality trait, alcohol use, and attitudes towards DUI. Discriminant function analysis explored the relative explanatory power of the grouping variables. RESULT Many offenders reported current excessive alcohol consumption. About 26-36% of the participants were potentially alcohol-dependent based on screening instruments/biomarkers. Cluster analysis identified five subgroups. The biggest subgroup considered their DUI a singular mistake and reported strong self-efficacy for avoiding further DUI (clusters 1 and 2). A small subgroup manifested alcohol dependence, psychological distress, higher impulsivity, and lower self-efficacy for avoiding DUI (cluster 3). Another subgroup exhibited a tendency to rationalise DUI, higher likelihood of future DUI, and lower self-efficacy for avoiding DUI (cluster 4). Most participants in another small subgroup abstained from alcohol use temporarily after their convictions (cluster 5). CONCLUSION The majority of DUI offenders regarded their DUI conviction as an exceptional mishap, while they continued consuming hazardous amounts of alcohol. DUI-specific attitudinal variables, including DUI rationalisation and self-efficacy for avoiding future DUI incidents, constituted a distinct aspect of the problem, suggesting the need to address this issue in addition to the underlying alcohol use problem.

Predictors of driving outcomes including both crash involvement and driving cessation in a prospective study of Japanese older drivers

The first aim of this study was to investigate predictors of future traffic crash involvement, taking into account bias in the handling of data for former drivers. The second aim was to compare characteristics of former drivers and crash-involved drivers in order to gain an understanding of appropriate driving cessation among older drivers. In all, 154 drivers aged 70 years or older participated in the baseline interview and the follow-up survey conducted two years later. In the baseline interview, participants were asked to respond to a questionnaire, take the Useful Field of View test® (UFOV), and complete the Mini-Mental State Examination. In the follow-up survey, participants were asked by mail or telephone whether they had stopped driving. Participants reporting that they still drove were invited to participate in a subsequent interview. Based on the information obtained in the follow-up survey, participants were classified as follows: driving cessation group (n=26); crash-involved group (n=18); and crash-free group (n=110). A multinomial logistic regression was then used to analyse the data. Contrary to the results of previous studies, we found older age to be associated with crash involvement but not with driving cessation. The cessation group had more decreased cognitive processing speed than the crash-involved and crash-free groups. Crash history was also predictive of crash involvement. Participants who were subject to license renewal between baseline and follow-up had a greater tendency to continue driving. Results suggested that age and crash history could potentially identify high-risk older drivers. The predictive power of cognitive processing speed is reduced under certain conditions. License-renewal procedures may induce Japanese older adults to continue driving. Future studies should use a large national sample to confirm the results of the present study.