Driving Evaluation and Fitness for Persons With Cognitive Impairments

Driving is an important activity for older adults because it is frequently related to personal independence, mobility, social interaction, wellbeing, and confidence. Dementia can impair older adults' driving. The current consensus is that people with moderate or severe dementia are too cognitively impaired to drive safely. Persons with Mild Cognitive Impairment (MCI), often considered a transitional state to dementia, and those with mild dementia can still potentially drive, although some require further evaluation to determine the driver's fitness to drive. Extensive research has been devoted to the development of fitness-to-drive assessments. However, very limited attention has been paid to whether the driving skills of drivers with MCI can improve and thus potentially prolong the driver's safe-driving years.

MCI is a common neurodegenerative disease in older adults, with a prevalence of 16-20%. It is estimated that 20-40% of the MCI population will progress to dementia. Despite the potential driving concerns, it should be noted that over 50% of people with MCI are considered safe drivers. Because un-warranted driving cessation may lead to depression, functional decline, and even increases in the family's care burden, researchers have guarded against the premature revocation of driving rights.

Recent studies exploring the driving behaviors of drivers with MCI have shown inconsistent results. For example, increasing difficulties and unsafe behaviors in driving can be considered early warning signs of possible cognitive impairment. There may be a connection between specific cognitive skills (such as flexibility of visual attention and executive functioning) and poorer driving performance on specific tasks, such as car-following and road-tracking. Drivers with MCI may encounter difficulties at intersections with stop signs or critical light changes, and with headway, driving speed, reaction time, and lateral control. However, the above studies were usually conducted with driving simulators.

Only a few studies have investigated the on-road driving performance of drivers with MCI. Wadley, et al. compared drivers with MCI to drivers with normal cognition on a standardized route with various driving maneuvers frequently encountered in daily life. The results showed "less than optimal" performance, such as statistically significant poor performances in overall driving skills, especially in lane control and left turns. Driving can become increasingly difficult, for the cognitive capacities of older drivers with MCI are likely to deteriorate over time.

Recent evidence has suggested that cognitive training can slow or even reverse the cognitive impairments associated with MCI. Cognition intervention have shown positive improvements in the immediate and delayed memory functions of persons with MCI after intervention. However, advances in cognitive training for persons with MCI have yet to be applied to driver rehabilitation.