Driving a vehicle is a dynamic activity, so requires a seamless interaction of multiple cognitive abilities. This paper describes an integrated cognition of human attention during the performance of a vehicle driving. Michon proposed three levels of driver behavior called strategic （planning）, tactical （maneuvering） and operational （control）. The strategic level involves route choice and the realization of the selected route. The tactical level concerns maneuvering. The operational level concerns vehicle control in terms of speed and course control. In this widely-cited model of driver behavior, executive function, attention, visuospatial function and global cognition emerged as the strongest factor for driving performance. In our experiment that measured oxy-hemoglobin levels of the drivers using functional near-infrared spectroscopy, significant activities were shown in bilateral frontal, temporal and parietal lobes, and were more prominent in the right cerebral hemisphere than in the left. For patients with brain injury, checking up the function of the brain region where the damage has occurred is important before providing sufficient real vehicle driving practice.

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In recent years, the number of elderly people involved in automobile accidents has increased. Persons with dementia （Alzheimer-type dementia, vascular dementia, Lewy body dementia, frontotemporal dementia） are not permitted to update their driver’s license. The Road Traffic Law has been updated and the license renewal procedure for the elderly has been revised. In addition, a temporary cognitive function test and temporary course for the elderly have also been developed. Going by the revision of the law, the number of persons for whom a dementia specialist's medical examination is needed is estimated to be 50,000 or more. The Supreme Court, on March 1, 2016, passed a judgment denying the compensation liability of the family of a person with dementia. However, because elderly persons suffer from many diseases, it is difficult to judge the causality between an accident and a disease during a criminal trial. There are various legislative issues pertaining to persons with dementia who drive. Therefore, further investigation on this subject is necessary.

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According to the 2015 Traffic Casualties by Conditions Report, deaths due to accidents during walking is the highest （37.3％）, followed by deaths due to accidents during driving （32.1％）, and deaths due to accidents during cycling （13.9％）. In addition, elderly people make up the highest percentage of deaths within bicycle group with 65.0％ and has the highest case fatality rate. From these, we can see that the higher the age the more one is susceptible to fatal accidents. Hence, prevention of accidents in elderly people is important. In this study, a Bicycling Simulator for evaluating the induction factor of traffic accidents was developed. A virtual traffic environment was developed using VR technology. Through simulation of road crossing, we were able to study the induction factor of traffic accident of road crossing while riding a bicycle. We measured the actions in the process of cycling down a straight road until end of road crossing of 18 elderly and 15 young participants. Our measurements showed that 0 case of young participants met with accidents and 30 cases of elderly participants met with accidents on Near Lane （17％）. From this result, we categorized participants that met with accidents 2 or more times at Near Lane as “High Accident Risk Group” and participants that met with accidents 1 or less time at Near Lane as “Low Accident Risk Group” and investigated the difference in movements between them. In our paper, we analyzed the movement of bicycle and movement of head of participants while cycling in VR space and calculated the time needed for final backward confirmation before entering the road and the time spent from final backward confirmation until entering the road. Moreover, we also calculated the distance between the bicycle and the closest vehicle that closes in from the rear of the bicycle during road crossing. As a result, we found out that the long time spent on the road during road crossing, short final backward confirmation period before entering road and long final backward confirmation period until entering road are reasons for the increase in accident risk.

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We conducted retrospective analysis with the aim of helping decrease the number of bicycling fatalities. We reviewed bicycling fatalities recorded in accident records from Shiga Prefecture, Japan, in 2013–2014, broken down by sex, age, cause of death, type of accidents, and situation of death. Obtained results were compared with nationwide data to elucidate characteristics of the accidents in Shiga. Victims were 28 bicyclists（21 male, 7 female ; mean age, 66.9±18.4 years）. Older bicyclists, aged ≥60 years, accounted for 75.0％ of all victims in Shiga, which was similar to the nationwide figure of 72.4％. Head/neck injuries were the most common cause of death in both Shiga（60.6％）and nationwide（68.5％）. In Shiga, motor vehicle–bicycle collisions were the most common type of accident（57.1％）, followed by single-bicycle/individual collisions（39.3％）and train-bicycle collisions（3.6％）. The proportion of motor vehicle-bicycle collisions in Shiga was significantly lower, and of single-bicycle collisions, was considerably higher than in nationwide figures（57.1％ vs. 84.6％, 39.3％ vs. 14.3％, respectively p<0.001）. Deeper analysis of single-bicycle collisions in Shiga found three victims suffered acute health changes while driving. Furthermore, eight victims（72.8％）of such collisions had fallen into a ditch. Among these eight, five were inebriated, with mean blood alcohol concentration of 1.7 ± 0.5 mg/ml. The results led us to recommend the following effective preventive measures against such fatalities: bicyclists should be in sound health, use of helmets should be recommended to protect against severe head injuries, and drunk driving should be monitored and regulated for bicyclists. Furthermore, improving road conditions, such as installing guardrails, covering ditches, and installing streetlights or reflectors, is required. To our knowledge this is the first report to intensively analyze bicycling fatalities in a specific area of Japan, and to subsequently propose effective preventive measures from a medical standpoint.

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To resume driving for the patients recovered from stroke, comprehensive support by occupational therapists and medical doctors has been performed in our hospital. Four males with the disturbance of cognitive function or higher brain functions were participated in the support program. Based on the physical examinations and neuropsychological examinations, adequate suggestion, prefer or stop driving, was advised. Then, permission to drive a vehicle was decided after an audit of the results of simple perspective, reaction tests and the reports by physician at the Public Safety Commission. For a patient without enough cognitive function to drive a vehicle, although medical staffs suggested avoid driving, the Public Safety Commission permitted to driving resumption legally. To adequately decide the driving ability, first, medical staffs must have thorough knowledge of the legal and practical aspects of resume driving. Then, promoting community integration is needed to enhance the resumption of driving for the stroke patients.

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To manage a rehabilitation program and support work resumption, we examined the rehabilitation processes of five stroke patients who had worked as taxi drivers. We analyzed the results of the following neuropsychological examinations: Mini-Mental State Examination （MMSE）; Kohs Block Design Test; Trail Making Test A and B; Paced Auditory Serial Addition Task; Behavioural Inattention Test （BIT）; Wechsler Adult Intelligence Scale III; and Wechsler Memory Scale-Revised （WMS-R）. We assessed driving ability using a simple driving simulator （Honda Safety Navi） and the Honda Driving Simulator, which is an interactive, realistic, and technically advanced simulator. All the patients had nearly normal cognitive function, with an MMSE of 28 or more, and displayed no inattention deficiency based on the BIT. Only one patient showed a lower WMS-R score than the reference value indicated in a previous study. With the other neuropsychological examinations, all the patients had higher scores than the reference values. In the beginning of the rehabilitation process, all the patients confirmed that they wished to resume driving. They then underwent standardized neuropsychological training and simulator-based driving training as both inpatient and outpatient rehabilitation. Additionally, two patients received on-road driving training. In the workplace reinstatement process, employers indicated that it was preferable that the patients initially return to non-driving jobs before resuming taxi driving. Reducing the driving duration, such as avoiding late-night shifts, was also indicated as desirable following reinstatement. In addition to reacquiring driving ability through rehabilitation, post-stroke taxi drivers need employer support with respect to working conditions. For such drivers to resume work, the cooperation of all related staff, such as physicians, rehabilitation therapists, employers, and driving school instructors, is essential for the care of these patients.

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