Turning movements, vehicle offsets and ageing drivers driving behaviour at channelized and unchannelized intersections

- We compared the crashes and turning movements of ageing drivers and younger drivers.
- Ageing drivers tend to make relatively sharper or tighter turns.
- They exhibit greater offsets during turning movements at both channelized and unchannelized intersections.
- They experience more intersection crashes, especially those involving turning movements.
- We recommend trialing the new intersection designs proposed by the FHWA (2014).

Ageing drivers experience a higher risk of intersection crashes because of their decrease in driving efficiency, including the decline in cognitive ability, head and neck flexibility, and visual acuity. Although several studies have been conducted to examine the factors associated with ageing driver crashes at intersections, little research has been conducted to examine the differences in the factors related to ageing drivers' turning paths and intersection geometric features. This study aims to improve the safety of ageing drivers at intersections by identifying the maneuvers that are risky for them and tracking their turning movements at selected intersections. We find that ageing drivers experience more crashes at intersections than younger drivers, especially crashes involving turning movements. Furthermore, ageing drivers experience more crashes at unchannelized intersections compared to channelized intersections. In addition, this study finds that ageing drivers exhibit greater and more inconsistent offsets during turning movements compared to those of younger drivers at both channelized and unchannelized intersections. Ageing drivers also tend to make relatively sharper or tighter turns than younger drivers. Hence, transportation engineers and road safety professionals should consider appropriate countermeasures to reduce the risks of crashes involving ageing drivers at intersections.