An Empirical Study of Measures for Preventing Crossing Path Collisions at Unsignalized Intersections—Development of Driving Safety Support Systems using Infrastructure-Vehicle Communication

Measures for preventing the very occurrence of traffic accidents are being viewed with increasing importance given the continued high levels of accidents. This study focused on the fact that the greater majority of traffic accidents occur because of drivers’ perception error concerning risk factors. A study was made of measures for preventing crossing path collisions at unsignalized intersections from the standpoint of improving drivers’ perception abilities. It was hypothesized that calling drivers’ attention to risk factors would help to avoid perception error and work to prevent accidents. Toward that end, two driving safety support systems are proposed that work in cooperation with the roadside communications infrastructure. Two systems can obtain and present to the driver as quickly as possible information on risk factors that drivers are apt to overlook. If necessary, the systems issue audible and visible alerts through the car navigation system to call the driver’s attention to a potential risk. The utility of these support systems as active safety measures was validated in a field operational test involving participation by 2,000 ordinary drivers.