Collision Avoidance Capabilities of Older Drivers and Improvement by Warning Presentations

The avoidance behavior of drivers over the age of 65 was compared with drivers under the age of 60 years in an emergent traffic situation where an obstacle vehicle drives into a blind intersection in a driving simulator. The drivers generally tended to do their best driving as the required reaction time in the situation decreased. However, the avoidance performances of the older drivers were more restricted than those of younger drivers; e.g., the maximum steering velocity was around 250 deg/s for the older drivers but 450 deg/s for the younger drivers. The older drivers needed a greater time margin, ranging from 1.35 to 2.7 s, than the younger drivers to successfully complete the avoidance. It was suggested that the avoidance abilities of the older drivers could be attributed to their mental and physical traits; their avoidance performances were remarkably improved by presenting advanced auditory warnings 3.0 seconds before their arrival at the intersection.