Elderly Drivers: Testing, Safety, and the Aging of America

Introduction: The Graying of America and Road Safety

Due to the population shift in the United States — commonly referred to as "the graying of America" — the next couple of decades will significantly increase the number of individuals over the age of 65 who are driving on the country's roadways. Because a variety of physical and psychological conditions either worsen or arise after the age of 50, and because older individuals are involved in a greater number of motor vehicle accidents, it would seem practical for proactive measures to be taken now. Special examinations should be developed and administered prior to re-licensing that test for the conditions most prevalent with aging, so that the safety of older individuals and others on the road will be protected.

The United States is entering the era of the graying of America. Increased life expectancy is creating record numbers of people aged 65 and older. In less than a century, the country has added 25 years to the average life span. Those aged 65 and older represented 13% of the population in 2000 and will constitute approximately 21% of the population by 2030. The group expected to grow most rapidly in the next 30 years is the cohort aged 85 years and older. As this shift occurs, the United States can expect a wide range of changes, from family structure to healthcare to cultural values.

Because of these demographic changes, more drivers on the roadways will be over 65 as well. In the next 20 years, the number of elderly drivers — persons 70 and over — is predicted to triple in the United States. What impact will this have on accident statistics?

A study was initiated to forecast the number of older drivers and passengers who may be fatally injured in traffic crashes in future years (Bedard, 2001, p. 751). The research was based on data from the United States Fatality Analysis Reporting System covering the period from 1975 to 1998. Results showed that approximately 35,000 drivers and passengers died in traffic crashes each year during that period. Older adults — those aged 65 and up — accounted for 10% of all fatalities in 1975, 17% in 1998, and a projected 27% by 2015, the same proportion predicted for drivers and passengers younger than age 30. On the basis of these projections, the number of fatally injured women and men above the age of 65 will increase by 373% and 271%, respectively, between 1975 and 2015. The researchers concluded that if present trends continue, the number of fatalities among older drivers and passengers may equal those among drivers younger than 30 early in this century. These projections call for further research into conditions that may lead to crashes involving older drivers, and for the development and implementation of initiatives to curb traffic-related fatalities among older adults.

Across the country, states are assessing the need for driver testing for the elderly. Pennsylvania law requires a doctor to report any condition that impairs a patient's ability to drive. Of 21,000 reports on questionable drivers filed with Pennsylvania officials in 2004, nearly 6,000 resulted in license suspensions, with 181 of those suspensions due to neurological disorders such as Alzheimer's disease. In Canada, drivers over 80 are required to take medical examinations before renewing their driver's licenses in British Columbia. Ontario drivers over 80 may be required to take a road test every two years. Florida, the state with the largest percentage of seniors, issues licenses for six years, but drivers over 79 must pass a vision test. Illinois and New Hampshire require drivers 75 and older to take a road test. The American Association of Retired People (AARP) recommends a refresher driving course for individuals over the age of 50.

Given the health changes that people undergo as they grow older, such policy decisions are well-founded. It would be unwise to wait until the situation demands a reactive response rather than taking proactive steps today.

Historical Background: Aging, Mobility, and the Automobile

A decade ago, it became clear that the future held both great promise and significant mobility challenges for the aging population. Today the evidence for both possibilities is even more apparent. By almost any measure, in the coming decades the elderly will enjoy longer, happier, and more fulfilling lives than their peers today — and certainly more so than the elderly of just a few decades ago. However, a 1996 Organisation for Economic Co-operation and Development (OECD) study surveyed the implications of global aging and commented:

"The basic news is good. Increased longevity, good health and independence are key values in their own right. They are also a reflection of the underlying strength of social and economic issues… [but] there will be difficult transitional problems before that good news is fully realized." (OECD, 1997, pp. 5–6)

One of these challenges will be automobile driving by an aging population. Older people today have much more active, eventful, and mobile lives. Mobility — defined principally as the trip rate by all forms of transportation, including walking, biking, driving, and using other moving vehicles — is an important part of their active lives, as is efficient, convenient, and flexible access to a variety of desired services and facilities. When aging individuals lose the ability or resources to engage in such activities, the decline in their well-being may be substantial and could have profound physical and psychological consequences. A direct source of decline among the elderly in coming decades will be decreasing mobility — specifically, the inability to drive or to find satisfactory travel alternatives to access needed services and facilities. No evidence exists that older people's desire to travel will decline simultaneously with their ability to do so. Many elderly individuals may eventually find themselves cut off from the very aspects of life that made their early retirement years so much better than those of older people only a few decades ago.

The number of Americans over age 65 has greatly exceeded the growth rate of the population as a whole, and this growth goes hand-in-hand with a significant shift in population structure. According to the U.S. Census Bureau's Population Profile of the United States (1998), the American elderly now comprise a major proportion of the entire population. There are two primary causes for the growth in both the number and percentage of older people. First, people are living longer due to increased income, better education, and improved healthcare. The Central Intelligence Agency World Fact Book indicates that in 1998, the average American life expectancy was just over age 76. When the United States was first founded, life expectancy stood at less than half that figure. Even at the start of the twentieth century, the average U.S. life expectancy was below 50 years (U.S. Census, Statistical Brief). Older Americans today are better educated and housed than their counterparts from just a few decades ago. They are more likely to be economically well-off and less likely to live in poverty. Until 1974, for example, the poverty rate of the elderly was greater than that of children. In the United States, the median income for elderly people more than doubled between 1957 and 1992, while the poverty rate was cut in half (Hobbs, 1996, p. 64). At the same time, chronic disability and institutionalization rates among the aging have continued to decline, and death rates from heart disease — the major killer of the elderly — have fallen substantially since 1960. A second reason for the growth of older populations is that individuals of childbearing age are having fewer children; fertility rates have continued to fall over the last 40 years.

Since the 1950s, Americans have become increasingly dependent on the automobile as more people moved to the suburbs, federal highway systems began dissecting the country, and national and city transportation systems started declining. Older people have also become more dependent on the private car, which has given them more personal choices, a greater range of possible activities, and greater independence. According to the report Transportation in an Aging Society (2004, p. 18), driver licensing among the elderly is very high and continuing to grow. Licensing rates increased for all individuals over age 50 from 1992 to 1997, with growth faster among women than men, especially those over age 70. This trend does not reflect people suddenly deciding to begin driving but rather younger, active adults aging into their retirement years. As a result, in 1997 almost 92% of all men and 70% of all women over 60 years old held a driver's license. Licensing is nearly universal among those turning 65 in the next 15 years. By 2012, almost every American man and close to 9 out of 10 women will enter their retirement years as licensed drivers. Presently, there are approximately 18.5 million licensed drivers aged 71 and over.

While the socioeconomic and health conditions and mobility of this aging population are better than ever before, this does not mean that problematic areas do not exist.

Physical and Cognitive Conditions That Impair Elderly Driving

As one ages, specific functions related to driving skills may become impaired, including vision, hearing, sensation, and cognitive and motor abilities. For instance, a decline in peripheral vision may affect the ability to pass approaching vehicles safely, and the decreased range of motion in an older person's neck may impair the ability to look behind when reversing. Reaction time decreases by almost 40% on average between the ages of 35 and 65 (Jackson, 1999).

The aging process may also affect cognitive skills. Short-term memory loss, for instance, can impair driving by interfering with an individual's ability to process information effectively when merging onto a highway or changing lanes. Such issues are magnified when driving under stressful conditions. The higher incidence of cognitive impairment — particularly dementia — among older men and women leads to an increased risk of accident involvement (Jackson, 1999).

According to AARP, as a group, persons aged 65 and older are relatively safe drivers. Although they represent 14% of all licensed drivers, they are involved in just 8% of police-reported crashes and 11% of fatal crashes. By comparison, drivers aged 16 to 24 are involved in 26% of police-reported crashes and 26% of fatal crashes, while representing only 14% of licensed drivers. Individuals over 65 also drive fewer miles on average than any other age group.

However, when they are involved in crashes, the circumstances and causes differ from those of younger drivers. Older drivers' crashes occur most often when turning left, whereas younger drivers' crashes typically occur while driving straight ahead. Older drivers more frequently fail to yield the right of way or fail to respond properly to stop signs and traffic signals, while younger drivers tend to speed or follow too closely. Among all drivers aged 65 and older, it is the oldest individuals who pose the greatest risk to themselves and to public safety. For adults aged 25 to 69, the rate of crashes per mile driven is relatively constant. The rate begins to rise at age 70 and increases rapidly at age 80.

In addition, aging drivers may not be aware of their decreasing driving ability. Seniors who are experiencing cognitive or physical decline should not be the sole judges of their own driving abilities. Research found that 98% of elderly drivers with impairments severe enough to hinder driving ability believed they were average or above average on the road (Corcoran, 2003, p. 16).

A common consequence of aging is a decline in motoric function and the ability to learn new motor skills. These declines are associated with increased risks of falling and mortality in older individuals. Musculoskeletal impairments can also affect driving safety. Conditions such as rotator cuff tendinitis may make turning a steering wheel more difficult. Under emergency conditions, an older driver may have trouble avoiding an accident or reducing its severity. Research has suggested that elderly drivers are more likely to be involved in accidents that involve turning or navigating intersections. Arthritis in the neck or shoulders may result in a limited ability to turn the head, reducing the capacity to scan efficiently for traffic at an intersection. Finally, reflexes often begin to diminish with age, placing elderly drivers at greater risk for a traffic accident.

Conclusion: Toward Specialized Testing for Elderly Drivers

Compared to previous generations, today's older adults are healthier, more active, and more likely to hold a driver's license. However, aging takes a toll, and accident rates begin to climb after retirement. By age 80 in particular, fatality rates per mile driven approach those for teenagers. While some of the increased fatalities among older adults can be attributed to greater physical fragility, another part of the problem is behavioral. Age-related impairments of vision, cognition, and motor function can interfere with the ability to recognize and react quickly to hazards.

The most frequently discussed approach to this problem is to retest older adults for license renewal. However, it will be necessary to devise specific examinations geared toward the limitations of the elderly, since standard tests — especially those for vision — are unable to predict which individuals are at risk for an accident.

A scientific approach to the problems of older drivers will require a fuller understanding of the behavioral and cognitive processes involved in driving. Recent research is beginning to fill this gap. One development is the Useful Field of View (UFOV) test, which assesses the span and speed of visual attention by measuring a person's ability to recognize targets flashed briefly in the near periphery — within approximately 15 degrees of fixation. The UFOV tests skills that are likely used in routine maneuvers such as lane changes and turns across traffic, where most accidents involving older drivers occur.

Another development comes from research on the visual guidance of locomotion that relies on ambient vision. Studies have found that for young drivers, control of steering and speed remains highly efficient even when central vision is degraded by low luminance or blur. By contrast, the steering ability of older drivers declines dramatically in low light. This suggests that, alongside age-related declines in central vision, full-field ambient vision also diminishes with age. Many older people compensate for these changes by avoiding risky situations, but developing a practical test of ambient vision may prove to be a valuable tool in assessing driving fitness among older adults.