RISK ASSESSMENT OF ELDERLY DRIVERS AT INTERSECTIONS: STATISTICAL MODELING

Advances in medicine and health care have caused an increase in the average life expectancy. This, along with the high birth rate after World War II, has caused an increase in the number of drivers in older age groups. Previous studies have shown that the elderly (defined herein as 65 years and older) are involved in a high percentage of accidents at intersections. Because of the continuous increase in the number of elderly drivers on the roads, it is also highly likey that the number of accidents involving the elderly at intersections will continue to increase, unless countermeasures that will reduce this high rate of intersection accidents are identified and implemented. This paper presents results obtained from a study which had an overall objective to identify intersection design and operation parameters that significantly affect the accident involvement of the elderly and thereby develop guidelines to reduce their accident involvement. Statistical models were developed relating the risk of accident involvement to the traffic and geometric characteristics of the intersection. The primary conclusions are as follows: (a) the elderly are more prone to perform a traffic violation when it is necessary for them to yield to opposing traffic compared with drivers of other age groups; (b) the provision of a protected left-turn phase with left-turn lanes will help in reducing the accident rates of the elderly at signalized intersections; and (c) longer amber times will be beneficial to the elderly.