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The present study clarifies the mechanism by which an accident occurs when an elderly pedestrian crosses a road in front of a car, focusing on features of the central and peripheral vision of elderly pedestrians who are judging when it is safe to cross the road. For the pedestrian's central visual field, we investigated the effect of age on the timing judgment using an actual car. The results for daytime conditions indicate that the elderly pedestrians tended to make later judgments of when they crossed the road from the right side of the driver's view at high car velocities. At night, for a car with its headlights on high beam, the average car-pedestrian distances of elderly pedestrians on the left side of the driver's view were significantly longer than those of young pedestrians at velocities of 20 and 40 km/h. The eyesight of the elderly pedestrians during the day did not affect the timing judgment of crossing a road.

The number of elderly drivers is increasing in Japan and ensuring the safety of elderly drivers is becoming an important issue. The authors previously conducted an analysis of the characteristics of accidents and traffic violations by elderly drivers based on the number of accidents in which they were rear-ended. This method was used in order to exclude the influence of driving frequency. As a result of that analysis, it was found that the likelihood of violations committed by elderly drivers was not particularly higher than in other age groups, while the likelihood of accidents caused by them was higher. The risk of causing an accident was judged to be about two times higher in elderly drivers than in the 35-44 year age group. However, the methodology presupposed that collisions in which a driver is rear-ended are accidents that occur randomly, and that they occur with the same probability in each age group.

The number of elderly drivers has been increasing in Japan with the rapid progress of the nation's population aging. Securing safety for elderly drivers is an important issue in Japan. In this paper, authors conduct analysis on characteristics of accidents and violations caused by elderly drivers based on data for 2009. As there is a tendency that elderly drivers generally have less opportunity to drive vehicles than younger drivers do, it is necessary to conduct this analysis considering driving frequency when making comparison among age groups. Then, we calculated the normalized ratio (odds ratio) based on the number of rear-ended accidents in order to exclude the influence of driving frequency. As a result of the analysis, it was found that the likelihood of violations committed by elderly drivers was not particularly higher, while the likelihood of accidents caused by them was higher than younger drivers.

Fuel cell vehicles that use high pressure hydrogen gas as a fuel should be able to immediately release hydrogen gas from the cylinder through pressure relief devices (PRDs) in the event of a vehicle fire. The release through PRDs prevents the cylinder from exploding due to the increased pressure of hydrogen gas, but the method of releasing the gas needs to be specified in order to avoid secondary disaster due to the spread of fire. Since hydrogen cylinders for fuel cell buses are different in terms of installation location and size from those for ordinary vehicles, the location of PRDs and the release direction of hydrogen gas should be separately examined. For example, the improper locations of PRDs would raise the possibility of explosion because of a delay in temperature rise, and the direct release of hydrogen gas from a cylinder installed on the rooftop of the bus may disperse the flame over a wide area.

Head-up displays (HUDs) require drivers to perceive double images simultaneously, that is, the scene to the front and display images, and this simultaneous viewing of two objects may cause cognitive confusion during driving. In this paper, we discuss some factors that determine the appropriate area for HUDs. First we discuss the feeling of troublesomeness with consideration of eye movements during driving. Secondly, we investigated the situation wherein the driver in a trailing vehicle perceives the stop lamps of a lead vehicle. Upon these considerations, we conclude that in the vertical direction the area under 4 degrees below the horizontal line would be a safer display area.