Abstract
Resource from BioMed Central.
The elderly represent the fastest growing driving population. Older drivers have a high crash rate per distance traveled, a high risk of injury or death in traffic accidents, and are commonly found to be ‘at fault’ in crashes. This reality has focused more interest on issues associated with the fitness to drive and the safety of older drivers. Many older adults depend greatly on their personal vehicle for transportation and suffer a marked loss of quality of life when, as a consequence of no longer being able or permitted to drive, their mobility becomes significantly restricted. The reasons for the deterioration of driving performance that occur during the aging process are multi-factorial and a great deal of research has focused on the identification of those factors. Nevertheless, some studies incorporating training programs have tried, with some success, to improve the driving-related abilities of older drivers. It has been demonstrated that physical activity can promote several skills that are associated with driving performance in older drivers. Few studies, though, have conducted exercise interventions among older drivers intended to enhance their driving-related abilities and promote road safety. In this context, the purpose of this work consists of examining the perceptual, cognitive, health, and physical factors related to fitness to drive in older adults and identifying possible strategies that can enhance their driving-related abilities. Moreover, potential mechanisms underlying the relationship among physical activity, driving ability, and road safety are discussed.
Introduction
Considering the data regarding road accidents and the demographic evolution, namely the increase in the older population, researchers and public health authorities are showing more interest in issues associated with fitness and safety to drive in older adults. In fact, older adults have become a larger part of the driving population and will continue to do so as “baby boomers” reach retirement age [58, 72].
In developed countries, the older population has become more dependent on their private cars and it seems very unlikely that other transportation alternatives can fully provide the level of mobility that older adults need [92, 93]. Driving is essential for older adults to continue their engagement in civic, social, and community life, and to remain involved in the human interactions necessary for health, well-being, and quality of life [26, 117]. Driving cessation has been linked to decreased participation in out-of-home activities and increased depressive symptoms [31, 66].
The number of crashes per distance traveled is higher in elderly drivers than in all other groups of drivers [38, 84]. Older drivers also have a high risk of injury or death in traffic accidents [55, 73] and are commonly found to be ‘at fault’ in crashes [84]. There is strong evidence that older drivers will make up a substantially larger proportion of drivers involved in fatal crashes in the next few decades. This is due to the proportional increase in the older population, the increment of the driving licensure rates, and higher annual distances covered [58, 72, 119].
Nevertheless, the crash rates for older drivers are lower per capita than for drivers of other ages since they drive shorter distances and are less often licensed to drive [58, 119]. Functional declines associated with aging appear to prompt some drivers to voluntarily change their driving habits [57, 104]; many older drivers report limiting their driving, especially to avoid complex driving situations such as peak travel times, night-time driving, and adverse weather conditions [9, 46]. However, because older occupants of vehicles comprise a large proportion of future deaths in motor vehicle crashes, public health efforts to reduce their morbidity and mortality should be pursued [58].
The most widely recommended road safety strategy for older drivers relates to the restriction of their driving licenses [113]. Nevertheless, this type of countermeasure needs to be carefully evaluated due to the negative consequences related to the restriction of elderly mobility, and increased emphasis should be placed on effective methods of protecting older drivers and passengers when they travel in vehicles [58].
Diverse perceptive, cognitive, and motor factors have been associated with driving difficulties and crash incidence in older adults. In a literature review, Anstey et al. [5] reported that measures of attention, reaction time, memory, executive function, mental status, visual function, and physical function were associated with driving outcome measures. Health status (e.g., cardiovascular illnesses, diabetes mellitus, state of depression, and dementia) has also been linked with the occurrence of crashes in older drivers [2, 73, 96].
Aging is associated with a decline in several cognitive skills and brain functions [17, 111] which can result in driving difficulties. For example, a decline in information processing speed, loss of efficiency in acquiring new information, cognitive inflexibility, a decline in executive functioning, a reduction in attentional resources, and a reduction in working memory function have been demonstrated [10, 111].
Interestingly, the practice of physical activities has a positive effect on perceptive, cognitive, and physical abilities as well as on health factors that are considered important for driving performance and safety among older adults. For instance, older people with a good physical fitness level show greater efficiency in information processing [29, 52], enhancement of attention capacity in dual-task situations [40], and better performance on tasks that require visual–spatial processing [102]. The effects of physical activity on cognitive factors seem to be more accentuated for tasks that request greater attention resources [22, 29, 116]. Furthermore, physical activity is a key factor for healthful aging [4, 120].
In this context, the purpose of this review is to examine the perceptual, cognitive, health, and physical factors that are related to fitness to drive in older adults and at the same time to identify possible strategies that could enhance their driving-related abilities. Moreover, we intend to identify and analyse the potential mechanisms that could support and promote a relationship between physical activity, driving ability, and road safety.