Safe Mobility In An Aging World
David Skinner
Mary D. Stearns
John A. Volpe National Transportation Systems Center
Research and Special Programs Administration
U.S. Department of Transportation
January 1999
Phone: 617/494-2696
FAX: 617/494-3622
E-mail: skinner@volpe.dot.gov
This paper has been prepared for presentation at the Annual Meeting of the Transportation Research Board, Washington, D.C., January 1999.
Safe Mobility In An Aging World
David Skinner
Mary D. Stearns
John A.Volpe National Transportation Systems Center
Research and Special Programs Administration
U.S. Department of Transportation
ABSTRACT
This paper presents issues related to individual aging, a growing aging
population, and the operation of private motor vehicles. The discussion progresses
roughly from demography and social factors, to health status, aging and motor vehicle
operating risk, determinants of mobility, economic status, and onto recommendations for
safe mobility -- the main theme of this paper. Not discussed are issues related to aging
and commercial and public operations in all transportation modes. These issues also are of
great importance. However, many of the issues discussed herein with some modification are
relevant to those areas.
There is a strong relationship between aging and motor vehicle
operation because time can lessen human capabilities like good vision, mental agility, and
physical dexterity -- all needed for safety. The demand to operate, however, remains
strong because of the benefits mobility (trip making) bestows in the modern age. In many
countries, a demographic transition is occurring, the result of an unprecedented,
simultaneous low birth and death rate. Countries experiencing this transition will have an
increasingly elderly population continuing to operate motor vehicles.
Generally, vehicle operators self regulate with compensating strategies
for age-associated deficits. With age, there is increased awareness of the risks inherent
in operating a motor vehicle. Such awareness allows older operators to make tactical-level
adjustments. As an example, visual limitations result in a reduction or even elimination
of night driving. When risks are deemed too great, many persons withdraw completely from
driving. However, the self regulation mechanism is not perfect. Data suggests some males
continue to operate beyond their capabilities while some female operators may withdraw
from vehicle operation prematurely. In any case, the concern is for a loss of safe
mobility and the decrease in social and physical well-being.
This paper stresses the need for prolonging safe operation by
retraining, making individuals aware of their deficits and the resulting risks to
themselves and others, making informed decisions, and to offer to older vehicle operators
mobility alternatives. Suggested are ways the benefits of mobility can -- and should be --
maintained after age decrements render safe operations unreasonable. There is also a need
for more work to uncover the relationships among medical conditions, drug interactions,
and changes in the risk of operating a motor vehicle. Also urged is investigation into the
differences between countries, and even regions of countries, on aging and operation
issues.
Because age groups have different rates, and, more importantly,
different types of crashes, highway safety programs must be optimized for age composition.
What is appropriate for one age cohort may not be so for another. Older drivers, in
absolute numbers, have fewer crashes of all types because they drive less. However, their
crash distribution shows a disproportionately high number of intersection crashes. Left
turns are particularly problematic for older vehicle operators. Thus, a need exists for
treating, at the operator and infrastructure level, the reasons for this difficulty. Crash
worthiness is also important. If older drivers are more likely to be hit from the side,
given the types of crashes they have, and the side has less protection, then adjustments
are called for to the struck and striking vehicles.
Keywords: aging, motor vehicle safety, accident, mobility
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ACKNOWLEDGMENTS
Some of the ideas contained in this paper are based on material
gathered and discussed during the writing of the report Improving Transportation for a
Maturing Society. The authors of this paper were part of a large team who worked on
that report. We wish to acknowledge the contributions of all who participated in producing
Improving Transportation for a Maturing Society.
Work on that report got underway in December 1995 when the then
Secretary of Transportation directed the United States Department of Transportation
(USDOT) to develop an overview of, and strategies for, the challenge of older operators
and travelers using all modes. As a part of that effort, five expert panels were convened
during March and April of 1996. The themes of those five panels were aging scenarios,
medical, management of transportation systems with aging issues in mind, human factors,
and alternative transportation. There were some sixty experts all together. As well, a
Steering Committee, consisting of one USDOT administrator representing each mode, provided
guidance and knowledge. Using the content of the panels and additional efforts, the report
was prepared.
It should be noted that issues discussed at these panels involved all
older operators and travelers using private, public, and commercial vehicles and all
modes: air, maritime, rail, highway, and pipeline. Again, the authors wish to thank all
who participated. Many of the ideas contained within this paper have the intellectual
lineage of the panels. Any misinterpretations of those ideas belong to the authors of this
paper.
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1. INTRODUCTION
At the end of the twentieth century, the world's population is aging,
particularly in countries in the industrial and post-industrial stage of development. The
reasons for the growth of the older segment of population are interrelated and
interacting: biomedical advances, containment of infectious disease, lifestyle changes,
rising per capita income, and other factors. With an aging population comes public concern
for safe, private motor-vehicle operation. For some of the increasing numbers of older
people, aging leads to the accruing of physical deficits related to the skills necessary
to operate motor vehicles.
Aging/mobility issues are briefly discussed below in this introductory
section. The same and related issues, along with some tables, are presented in more detail
in following sections.
1.1 Scope
Much of the discussion in this paper is based on the experience of the
United States with aging and motor vehicle operation. This information will be valuable
for other countries undergoing an aging transition. Countries such as Japan, Australia,
Netherlands have had more experience in maintaining safe mobility for older citizens. In
these countries, the aging issue now has risen to public and political prominence.
The discussion is limited to the operation of private motor vehicles.
Hence, not discussed are issues related to aging and pedestrians, aging and commercial and
public motor vehicle operations, and the significance of an aging operator population for
other transportation modes. These issues are also of great importance to society. However,
many of the issues discussed here for private vehicles are, with slight modification,
relevant to other transportation operations.
?Mobility,? in this paper, is defined as a transportation specialist
would use it, i.e., trip making with attributes of origin, destination, linking, etc.; and
not generally as the demographer would, as settlement or residential patterns. Mobility is
thought of as a derived demand for goods, services, and social interactions. This latter
aspect is important in the consideration of aging issues. The trips, and characteristics
of those trips, made by older persons will depend on their wants and command over goods
and services, and desires for social interactions. Thus, the aging and mobility issue
implies a sequence of topics to arrive at recommendations for the goal of safe mobility.
This paper discusses the following topics: population growth and
structure, social characteristics such as family formation, health status, aging and motor
vehicle operating risk, determinants of mobility, economic status, and recommendations for
safe mobility.
1.2 Benefits of mobility
In industrial or post-industrial societies, where there is dispersed
land usage, mobility grants access to goods, services, and social interactions. The
benefits that mobility brings can be social, economic, physical, and, even, emotional in
nature. In fact, being mobile becomes a precondition for full participation in these
societies. Bringing things to people in their homes is not a sufficient solution.
1.3 'Operational' definition of aging
Aging is defined demographically as (1) an increase in the average, or
median age, of the entire population; and/or (2) an increase in the relative proportion of
older persons. The category "older" is defined by chronology, often at age sixty
or sixty-five years. Many employment and income supplement programs use chronological
boundaries. However, there is no chronological boundary established for the cessation of
motor vehicle operation in the United States.
Aging, in biological terms, is the slow, but cumulative, buildup of
physical and cognitive deficits. There is much individual variation in the aging process
but no one escapes. Because motor vehicle operation requires sensory-motor skills, there
must be a relationship between aging and driving. Motor vehicle operation requires the
driver to make a continuous visual search for information, process that information, make
decisions, and provide physical inputs. Physical decrements, such as poor eyesight or
cognitive limitations due to dementias, such as Alzheimer's disease, may make safe motor
vehicle operation problematic.
The variability of performance within any age category increases with
the age category. The expanding range of performance differences among individuals through
the course of a life span make chronologically-based policies intractable. Because
chronological age is associated with variation in physical and mental capabilities, there
is no chronological age when all people must curtail or cease vehicle operation. It should
be noted however, that when safety is critical and there is no tolerance for error in
operation, as a society, we adopt chronological age limits.
Although the "aging" population is frequently defined as
counted as beginning at 65 years, the risks associated with motor vehicle operation
increase exponentially at age 75 and older. For this reason it is important to examine the
growth in the population age 75 and older. The crash data suggest that motor vehicle
operators age 70 or 75 face a rapidly escalating crash risk . In the United States, crash
involvement increases on a per mile driven basis by age 70 to 75. Because older drivers
tend to avoid safer driving as on limited access roads, they may have a disproportionately
higher risk of crash involvement. This is shown by their higher relative involvement in
intersection crashes.
Despite age-related impairments, the probability on a per mile or
capita basis, of any particular elderly operator getting into a crash is low. The
cumulative increase in deficits associated with aging does not translate proportionately
into higher crash rates. Generally older people have an offsetting awareness of the risks
involved in motor vehicle operation that allows them to compensate or withdraw from
driving.
On average, older operators have elevated rates of crash involvement as
they do for some other types of unintended injuries and diseases. But many in that age
group operate vehicles and do so safely.
The normative question for society is to address is what is an
"unacceptable risk." How can a society get operators approaching the risk
threshold to accept it? What alternatives can be offered to someone who should not operate
a vehicle? If society expects older drivers (or for that matter any drivers) to make
rational decisions, there must be rational alternatives. The challenge for those impaired
-- and society -- is how to maintain mobility, first by allowing persons to go on driving
appropriately and then by offering alternatives and substitutes for personal mobility.
1.4 Future health status of elderly
The projections of relative and absolute increases in the number of
older people are certain because they are already born. However, the health, lifestyle,
and social characteristics are not as firmly established. A 70-year-old person in the next
century will not have the same health status as those people currently 70 years old. It is
likely they will be healthier, although not without some chronic afflictions. Some will be
wealthier and even more accustomed to mobility and motor vehicle operation. These
lifestyle changes will have a profound effect on the propensity of older people to operate
vehicles safely.
1.5 Elevated risk
The age distribution of a population has a relationship to the absolute
number of crashes. When injury and fatal crashes in the United States are plotted by age,
the curve has a flattened U-shape as shown in Figure 1. Drivers with the lowest accident
rates are in the middle of the age range, between 35 and 55 years old. Younger and older
drivers have more elevated rates.
At present, Figure 2 shows that there are more persons, in absolute
numbers, in the lower-rate middle of the injury and fatality crash curve due to the age
profile of the baby boomers in the United States. This distribution suggests that the
actual incidence of crashes is as low as possible without improvements in vehicle
operation and road design. If the age composition has more of the population concentrated
at the beginning and the end of the age range, there will be more crashes for a same size
population. The deduction is that the injury and fatality rate due to motor vehicle
crashes is now as low as it can be. As the baby boomers age, the sheer size of this group
will amplify the increased injury and fatality rate associated with older vehicle
operators.
Injury and fatality rates based on age represent the collective
experience of that population segment. The individuals in any age category display
variation. The range of variation in vehicle operation is particularly true for older age
groups. Some older operators with identifiable health conditions have
an elevated risk of operating a motor vehicle. There is a need for more research to
understand how risk is distributed among members of older age groups. Older operators with
a variety of health afflictions are likely to be most at risk. They also are likely to
lack mobility alternatives.
1.6 Aging and human performance
Operators should be considered as essential as the technical components
as vehicles become more complex. The human factors approach provides a way to understand
vehicle operation as a system composed of people and technology. The use of human factors
knowledge should encourage engineers to design in relation to users. The resultant
products would feature ease of use and, as a result, appeal to an expanded market. The
Baby Boom population, over 70 million, is now starting to have failing eyes and yet there
are displays on windshields.
Human Factors has two components; "knobology," the physical
part and the information load. The latter, information load, varies with stress and
fatigue which can be caused by, for example, night driving, fatigue, or poor eyesight. ITS
design requirements can be worrisome because users may be near-sighted, left-handed,
dyslexic, presbyopic because people who can afford ITS (Intelligent Transportation
Systems) options tend to be older. There is a need to design environments which allows
some forgiving.
A substantial component of the human factors data used for design
parameters was generated by research conducted during World War II. Most of that data
measured vision and hearing. The available standards come from military research and
standards developed during and after World War II. Software designers need to understand
the cognitive process but there is little data available about motor performance and
cognitive areas such as memory performance, reaction time, and other human performance
topics. There is a need for a data infrastructure to be able to asses how parameters
change with aging to support design. There are no studies which systemically explore these
variables and this would be useful knowledge to update national and international
standards.
1.7 Retirement trends impact mobility
The timing of retirement, the subsequent choices of residential
location, and the amount of retirement income will all influence the mobility and
trip-making patterns of older people. Some people will continue to work past the
traditional age of retirement, full- or part-time. (As an aside, this is an issue for
commercial and public drivers who want to remain in their occupations.) In the United
States the land usage is dispersed and activity centers are not collocated.
There are a variety of decisions made about residential location in
retirement. "Most adults remain in their own homes or communities after
retirement." (Treas, p.10). This is referred to as "aging in place." As a
result older people may increasingly find themselves living in areas where shopping,
entertainment, and socializing may be linked only by roads and often lacking public
transportation. However there is a highly selective interstate migration of elderly
people. This migration lows out of a large number of states and into a few states. The
elderly who migrate tend to be the younger elderly and have higher incomes. (Treas) These
residential decisions of older Americans need further study to determine the consequences
for mobility.
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2. DEMOGRAPHIC TRENDS
2.1 Age profiles
The size of the population depends on three factors: the fertility
rate, morbidity rate, and the net of immigration and emigration. Many countries are
experiencing the maturing of the baby boomers, those born after the World War II, from
1946 to 1957. Fertility rates during that period in the United States were high but
precedented. The net increase was due to the reduction in death rates for children and
adults. This decline in mortality rates is also occurring in many developed countries.
Starting in 1958, there has been a historic decline in the birth rate in the United
States. The low birth rate should also be considered in evaluating the age profiles.
The increase in longevity due to healthier lifestyles and medical
advances has not brought health without infirmity. In fact, one of the important issues
for motor vehicle safety is whether there is an increased prevalence of chronic disease
among the elderly. The age distribution of young, middle, and old age is shown for
countries with population in 1995 greater than ten million in Figure 3. A number of
countries now have at least 10, and in some cases, 15 percent of the population over
sixty-five years of age.
In many countries the median age of the population is increasing. In
1995, as shown in Figure 4, in the United States there were 33.7 million people over the
age of 64. The U.S. Census Bureau projects that in the year 2000 there will be 35.3
million persons older than 64 years; in 2010, 40.0 million; by 2030, 70.2 million; and by
2050, 80.1 million. In 1995 those aged 80 and older represented 11 percent of the 64 and
older population; by 2010, they will represent 15 percent.
The United States is not alone in experiencing rapid growth in the
numbers of elderly. By 2010, the growth rate of the older population, age 60+, will be
three and one half times greater than the growth rate for the total population. Figure 5
gives life expectancies for various countries.
2.2 Gender
There is differential survival by gender which is increasingly a
world-wide phenomenon. The average life expectancy of a female in some countries may be as
much as five or more years longer than that of a male. Over time this difference may
decline, but it will persist if the causes are genetic and not just lifestyle. This
differential has implications for safe mobility. Women generally have lower crash rates by
age. Women are not as likely to have funds to support mobility at the levels of males,
having earned less, and likely having smaller pensions. Some women may over compensate and
give up driving prematurely.
2.3 Other social factors
It is likely that the health characteristics of the older population
will influence the number of motor vehicle crashes. Physical and mental capabilities
influence the rate at which crashes occur. Social factors determine who drives and how
much. Marital status, household and family composition, gender, and employment status all
influence driving, and the risk distribution of that driving. These social factors are
changing and shifts may have consequences for vehicle operations. The highway safety
community needs to monitor these shifts to enhance the effectiveness of safety programs.
2.4 Age structure and entitlement
The age structure and composition have implications for social
security, pension, and health insurance. Retirement income is an important determinant of
mobility, especially if alternatives to operating are necessary.
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3. HEALTH OF THE AGING POPULATION
3.1 Longevity
There has been a continuing decline in the death rates in many
countries. Childhood and adult mortality and deaths from crashes have been reduced. In
some countries, life expectancy has been extended by as much as five years. The question
arises whether this increase in life expectancy is also accompanied by increased
morbidity. The chronic and worsening health conditions accompanying longevity can have
strong effects on motor vehicle operation.
3.2 Links from health status to driving risk
It is difficult to draw an explicit link from age, to medical
condition, to functional disabilities (both physical and cognitive), and, finally, to
operator performance. Vehicle operators have many ways of compensating. There is not a
path from medical conditions to a certainty of a crash. The simultaneous change in driving
behavior that accompanies a physical condition makes any statistical estimation difficult.
With biomedical progress, the incidence of some diseases will be lessened; but others,
more chronic, will increase in prevalence. There may be a substitution of increased
morbidity for deferred mortality. There is a need to inventory the prevalence of physical
and cognitive conditions.
There is a changing disease mix among older persons. There is a need to
understand how different impairments affect the capability to operate a motor vehicle.
Such understanding presupposes the knowledge of what capabilities are needed to operate
motor vehicles. We must understand what remediation is appropriate for specific
impairments and what warnings should be placed on certain types of driving.
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4. MOTOR VEHICLE OPERATION AND RISK
4.1 Crash experience
Older operators of motor vehicles have fewer number of absolute crashes
of all types than those of other age groups, but they also drive less. Relative to their
number of crashes, older operators have a higher frequency of crashes at intersections.
They have trouble turning left when immersed in traffic. Traffic conflict and congestion
are not going away. The rush 'hour' now is spread over longer periods. There is traffic
congestion even in suburban areas during off-peak, daytime periods when the majority of
older operator driving is done.
On a per capita, or license, basis, older drivers have relatively low
rates of crash involvement. But on a per mile operated basis, their rates are as high as
young operators. This is especially true for those operators 80 years and older who have
the highest crash rates on a per-mile driven bases.
Rates of older operators appear higher because they drive most of their
miles in traffic. They do not drive as often on safer, divided highways. In the case of
fatal and severe injury crashes, fragility and frailness are also factors. The fatality
rate per crash starts turning up around age 60 and appears almost vertical by age 80. But
this may not be a good predictor for an individual because of increasing variation in
capability with age. At any age, serious crash involvement is a low probability event. For
example, only one out of 100 elderly die due to vehicle crashes compared with 1 out of 3
teenagers, age 16-19.
The United States is not alone in experiencing higher fatalities rate
among aging operators. Figure 6 shows motor vehicle fatalities per capita by age for
different countries. Portugal, Greece and Japan report a higher incidence of road accident
deaths for people age 65 and older than the United States. Countries with higher road
accident deaths per 100,000 for all ages than the United States include Portugal, Greece,
Belgium, Austria, New Zealand, and France.
The data in Figure 7 for the United States shows that because older
operators do not drive proportionately as much at night, fatalities are less. Figure 8
also shows that the increases in older-age fatalities are occurring during the day,
defined as the period 6:00 a.m. to 6:00 p.m. Recognizing the temporal distribution of
these risks, it is useful to allocate highway safety efforts accordingly.
The United States is not alone in experiencing a higher fatality rate
among aging operators. Figure 9 shows motor vehicle fatalities per capita by age for
different countries. Portugal, Greece and Japan report a higher incidence of road accident
deaths for people age 65 and older per 100,000 per licensed driver than the United States.
Countries with higher road accident deaths per 100,000 for all ages than the United States
include Portugal, Greece, Belgium, Austria, New Zealand, and France.
4.2 Crashworthiness and fragility
Older operators have a high relative number of crashes at
intersections, merges, and other locations requiring turning maneuvers in the presence of
traffic. Hence, the most vulnerable and frail operators are being hit relatively more
times in the part of the vehicle where there is the least crash worthiness -- the side.
4.3 Driving times of older and younger operators overlap
Older drivers concentrate their driving in the afternoon. They have
interactions with younger drivers and pedestrians at that time. The interactions among the
young and older cohorts with different driving styles warrant study. Likely operating a
motor vehicle is not going to get any easier where traffic congestion and conflict in
driving styles are concerned.
4.4 Operating strategies and decision making
Most older operators make rational decisions about when and where to
drive or whether to drive at all. They are successful in substituting good judgment for
loss of physical and mental skills. Gender also plays a role in this decision making.
Experts offer that some older males persist in operating too long while some older females
withdraw from operating prematurely. Mobility is especially important for females who live
longer and have less pension income.
Although choices exist as to when to drive, the nature of motor vehicle
travel is that of a derived demand for goods, services, and social interactions. Some
demands will occur at specific times as scheduled events, i.e., doctor visits, concerts.
There cannot be complete flexibility in trip timing. Hence, there is some loss of utility
from using conventional compensating strategies.
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5. LAND USE AND DEMAND FOR MOBILITY
5.1 Mobility
The interactions among retirement patterns, medical and health
advances, lifestyles past and present, pension programs and many other factors, produce a
unique set of derived travel demands. The demands have origins, destinations, and linkage
patterns to the goods and services older persons want to consume. 'Mobility' is used here
to mean both settlement pattern and, interrelatedly, trip making. Older persons require
mobility for more than just shopping for essential needs. Social interactions and
maintaining friendships require travel also.
5.2 Retiring in-place
An aging population, coupled with dispersed land use, will create more
demand for transportation. It is unlikely that older persons, especially those with
pension income, will cluster together in cities. They most likely will want to continue
their independent lifestyle built upon years of mobility while living in low density
areas. People tend to remain after retirement where they have lived. There are exceptions
where persons cluster in retirement communities. Some who have moved away after retirement
return to be near family or medical facilities when they become dependent or ill.
5.3 New forms of private and public transportation
Because many older people will, at some time, be unable to drive in all
circumstances, they need alternative transportation. Public transportation must be more
'older-user friendly'. But for places that older persons want to go, and not served by
existing public services, there is a need for flexible and demand-responsive alternatives.
The appearance of new transportation forms may be another manifestation of the emerging
volunteer sector. There are not the population densities to support traditional public
transportation forms. Volunteer-based, low-fare services are needed.
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6. ECONOMIC STATUS AND IMPACT ON MOBILITY
6.1 Dependency ratio
The maturing of the baby boom in many countries has now resulted in a
sizable group of people approaching retirement age. They will have an increased number of
years to look forward to in retirement because of biomedical and lifestyle improvements.
They have expectations for a productive retirement which will include mobility.
The decrease in fertility rates and the early retirement of some older
workers, some believe, will result in a smaller work force to fund programs for the
growing number of older persons. This is an increase in the dependency ratio, as shown in
Figure 10. A dependency ratio of, say, 0.50 indicates that for each person 15 to 65 years
old there is one-half of a person under the age of 15 or above the age of 65. However,
even if so, immigration, incentives for older workers to return to the work force if only
part time, and more capital investment per worker can mitigate any shortages.
What can be funded depends on the dependency ratio -- or does it?
Economic mechanisms can compensate. These include immigration, increased labor force
participation, increased capital intensity and other productivity gains, and job
restructuring which could include older workers.
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7. RECOMMENDATIONS
7.1 Recommendations
Much can be done to prevent any undue safety impacts from an
increasingly older population operating private motor vehicles. The following
recommendations are suggestive of directions to be explored and are not inclusive.
7.1.1 Social and political process
The social, political, and economic influence of older persons will
influence policy toward development of alternative transportation systems. Licensing
programs that place restrictions based on chronological age for older persons are likely
to be met with strong opposition. There is a need for alternatives to age-based operating
rules. However the current view is that chronology is the only objective method.
A more equitable approach would be to make driving/mobility decisions
performance based. This is difficult to do because of the need to establish a quantifiable
link between a performance deficit, or deficits, and performance. For example, when
physical or mental declines are assessed, it is the middle, not the early or late stages,
that present difficulty for evaluating performance. There are also risks due to conditions
not recognized, diagnosed, or treated. By contrast, properly treated conditions may pose
little risk.
There is a need to identify what are the links between physical and
mental declines and performance declines. There is a need for risk assessment data because
society needs to understand explicitly what level of risk it is willing to assume to
ensure mobility. Part-task simulators have the potential to be a major aid in evaluation
but currently their critical features have not been identified.
At present there is a lack of objective measures of safety critical
performance for testing older operators. Short tests may not reveal deficits or may
actually make driver appear to be worse than he/she is. There is a need for in-situ tests
which monitor driver for extended period in actual driving environment.
There is a need to re-conceptualize regulation because no one wants to
be the licensing gatekeeper.
Currently the responsibility passes between relatives to physicians,
occupational specialists, and the DMVs. Liability issues influence the likelihood of
health care workers to reporting people relative to motor vehicle operation. People with
marginal impairments may not seek help from physician for fear of licensing forfeiture. It
is possible that better training in this area could significantly enhance primary
physicians' contributions. There needs to be a shift from an adversarial to supportive
approach to provide ways to aid an aging operator to make the right choice.
7.1.2 The aging as a expanding travel market
Private transportation must accommodate the aging traveler because they
will increasingly have the interest in and resources to continue to be mobile. Currently
the accessibility of air travel and its support facilities such as restrooms can be
challenging. To make travel more elderly friendly, the 'aging option' should be built into
vehicles and infrastructure and fragility should be considered in design of vehicles.
7.1.3 Public transportation
Public transportation is part of the answer to aging mobility. There is
a need to redefine the concept of public transportation for aging users. It should
emphasize low cost technologies and calibrate occupant protection to the aging. Public
transportation should emphasize security and accessibility. It should not confuse
or burden aging operators. Better access, more security, rest rooms, places to sit while
waiting, readable signage, and courteous employees are all necessary for elderly
patronage. Existing public transportation needs to be made more elderly friendly. Yet
public transportation, even with improvements cannot completely fill the need, especially
in low-density areas.
At present alternative mobility services are fragmented. There
is a need to inventory existing mobility services including demonstration projects and to
identify their strengths, weaknesses, and gaps in services. The goal should be to foster
cooperation among providers. It might be possible to retrofit existing fleets, like school
buses, for use by the elderly. Better infrastructure design might encourage use of more
walking. Assisted living facilities which incorporate mobility services may reduce need
for mobility.
7.1.4 Human factors improvements
There is a need for human factor improvements such as vision aids and
collision warning to give the vehicle operator more decision time. Advances in technology,
including low tech, can help aging operators and are coming soon. Human factors
improvements may extend an operator's decision time. Simple improvements such as increased
brightness and larger letter size on signs, or reduced clustering of signs at intersection
can help. It is important to maintain road markings and signs to original specifications.
It would also be useful to foster more standardization of controls and displays in
vehicles. The goal should be to design and create vehicles and infrastructure that are
'elderly friendly'. Loss of bone and muscular strength make aging more vulnerable.
Occupant protection should be calibrated to the aging.
Advances in technology can help aging operators but enhanced technology
should resist complexity. Performance-aiding and safety features can be commercially
successful because experience with compliance with the Americans with Disability Act shows
that the required features were useful to all users. Aids for aging may be beneficial to
all although relief from product liability may be required to stimulate their
availability.
7.1.5 Document the functional content of tasks in non-commercial
vehicle operation.
There is a need for a better understanding of the
driving/flying/piloting task. It is critical to understand what operators actually do.
Acquisition of this knowledge would make it possible to develop performance based
standards or operating tasks for all modes. It would then be possible to define impairment
relative to specific task. The medical community must know what performance standard is
desired if they are to act as judges of performance.
7.1.6 Transportation alternatives
There is a need for new forms of public transportation. Such
transportation may actually be based on public-private cooperation. Any new forms of
transportation should be demand responsive to the lifestyle of older people.
7.1.7 Understand the relationships among age, drug use, alcohol,
impairments, and fatigue.
The aging may be more affected by drug use, alcohol, impairments, and
fatigue. There is a need to better understand effects of medication on operating.
Liability concerns may have overstated side effect descriptions. Newer drugs have fewer
sedating effects. The effects of fatigue and sleep apnea are important consideration for
older operators.
7.1.8 Training
People can learn at any age although rates and methods may differ.
Training and, more specifically retraining and refresher courses, have the potential to
make older drivers safer and more aware of their deficits and limitations. These programs
exist and some wisely begin before the operator actually needs to make age-related
modifications to driving. As an example, the American Association of Retired Persons
(AARP) has a program, 55 Alive. Hence, the older operator can make more informed decisions
about when and if to operate.
To maintain skills, they must be used or practiced continually. It is
known the recentness of training and experience impacts performance the most. It is easier
to train to compensate for physical deficits than for mental deficits. Similarly the
trainers and the training content must be sensitive to the needs of the aging.
As people live longer, any type of training or human capital investment
has increased benefits. Older operators need to be kept abreast of new traffic regulations
and operating practices. Older operators should be advised, as should all drivers, to use
their vehicle restraint system (lap and shoulder) and to properly position themselves as
drivers or passengers in a vehicle having airbags. Older drivers should be aware of
strategies to avoid difficult types of driving such as rush hour, intense sunlight,
slippery conditions, and the like. Older drivers should be cautioned to keep a
vehicle-following gap commensurate with their braking perception and reaction time.
7.1.9 Licensing
There is a need to create uniformity and cooperation in licensing.
Currently the states vary in the procedures they use to evaluate aging. Objective criteria
are very scarce and, as a result, DMVs remove relatively few from driving. Testing options
have their limitations because aggressive testing can give false positives and periodic
re-testing of all drivers may be too costly. Also, with episodic health declines, periodic
testing is not timely or effective. On-road testing is relatively subjective. There is a
need for non-adversarial procedures but performance based testing can be very costly.
Health practitioners need objective descriptions of risk to make informed evaluations.
Licensing and de-licensing are based on physical and mental health.
Licensing should involve eye exams that can detect conditions detrimental to driving, such
as those involving night vision. There is a need to develop new instruments for testing,
detecting, and tracking age-related deficiencies that impact the risk of operating.
Doctors and other medical professionals generally do not want to be
gatekeepers for private operators. They see their role as advising rather than adversarial
-- feeling patients will not be honest about treatable conditions if they know the doctor
is required to report.
7.1.10 Crash avoidance technologies and driver aids
There are few decrements to vehicular operating that technology and
ergonomics could not overcome. However, it may not be possible to overcome cognitive
deficits and dementia. Development and deployment of crash avoidance technologies to aid
older drivers are to be encouraged. But these technologies must be made elderly friendly
and accommodate the fragility of the elderly skeletal structure. Unintended safety hazards
resulting from the use of these technologies must be fully understood.
7.1.11 Infrastructure
The vehicle infrastructure can be made elderly friendly by eliminating
traffic conflicts at intersections, rotaries, ramps, and other locations of confluence.
These improvements would actually benefit all highway users.
7.1.12 Signing
Road signage must become more standardized. Signage should be
compatible with the physiology and perception-reaction capabilities. Various levels of
government, including municipal, should plan and budget for upgrading signage -- and
maintaining by appropriate repainting.
7.1.13 Need for Caretakers
Volunteerism could augment changing family roles. The higher proportion
of individuals in the workforce reduces the availability of volunteers. Due to the
declining family size and dispersion of relatives there will be an increasing need for
caretakers for the elderly. Because the 'young' old may use low wage jobs to supplement
retirement income, it might be possible that they could assist the most impaired.
7.1.14 Transportation planning
People need to plan for their future transportation needs just as they
do for other aspects of retirement. They should include in estimating financial needs for
retirement as a line item, alternative transportation expense, for the time when they are
no longer able to operate a vehicle.
7.1.15 Needed research
There is a need to collect data on older operator performance. There
are few longitudinal studies. One such issue that could benefit from this type of study is
the linkage between a medical condition and the likelihood of a crash. Constant reporting,
such as an older operator status report, is to be encouraged. Identification of the types
of crashes of older operators should continue to detect changes and emerging trends that
are remediable by technology, infrastructure, and/or training. Research is warranted on
effects of various drugs, and drug interactions, on the ability to operate.
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8. SUMMARY
Evidence suggests that mobility is essential and must be maintained as
long as possible. Mobility is important to a persons social, physical, and mental well
being. Many countries are undergoing demographic transition. The older segment of the
population is growing both relatively and absolutely.
At some point, it may not be prudent to continue to operate a motor
vehicle. Most older operators are aware when this time arrives. But some operators need
guidance in understanding the risk they present to themselves, their families, and others.
Those who do not operate should have alternatives so they gain the benefits of mobility
and avoid debilitating isolation. There is a need for new concepts of demand responsive
transportation systems with low cost structures and perhaps volunteer staffing. It is
necessary to supplement and/or support vehicle operation and to offer mobility
alternatives. The issue of aging vehicle operators is likely to increase worldwide faster
than rate of population growth.
At this time technology should be viewed as a resource. Because older
consumers tend to have a disproportionate share of the society's wealth, their mobility
represents a market opportunity for the private sector to capture.
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REFERENCES
Kinsella, Kevin and Yvonne J. Gist. International Brief Gender and Aging, Mortality and Health. US Department of Commerce, Economics and Statistics Administration, Bureau of the Census, IB/98-2, October 1998
National Institute on Aging. "Aging in the Americas into the XXI Century," U.S. Department of Commerce, Economics and Statistics Administration, Bureau of the Census. August 1998
Schaie, K. Warner and Sherry L. Willis Adult Development and Aging. 4th Edition, New York: Harper Collins, 1996.
Treas, Judith,"Older Americans in the 1990's and Beyond," Population Bulletin, Vol. 50, No.2 Washington, DC: Population Reference Bureau, Inc. May 1995.
U.S. Bureau of the Census, Current Population Reports, "Population Projections of the United States, by Age, Sex, Race, and Hispanic Origin: 1993 to 2050," U.S. Government Printing Office, Washington, D.C., 1993, Table 2.
FIGURES
Figure 1: Motor Vehicle Fatality Rates per 100,000 Licensed Drivers by Age
Figure 2: Population Projections for U.S. Residents
Figure 3: Age Composition of Nations with 10 Million or More Inhabitants: 1995
Figure 4: Age Distribution of United States Population Age 65+
Figure 5: Life Expectancy at Age 65 by Sex for Selected Countries, 1987 and 1992
Figure 6: Age/Fragility Relationship
Figure 7: Road Accident Deaths per 100,000 All Ages, 1994
Figure 8: Day and Night Fatalities with a Driver Older Than 64 Years of Age
Figure 9: Road Accident Deaths per 100 Age 65 Plus, 1994
Figure 10: Dependency Ratio, 1995
FIGURE REFERENCES
Figure 1: NHTSA Research Note, October 1995
Figure 2: U.S. Bureau of Census
Figure 3-5: United Nations, "World Resources 1994-1995," Tables 16.1, 16.2, and 16.3, Oxford University Press, New York, 1994. Republished: "The Population of the United States".
Figure 6: National Center for Health Statistics. ?Health United States?.
Figure 7: Transport Statistics Report, International Comparisons of Transport Statistics. Government Statistical Service. Norwich, England, 1997.
Figure 8: Fatal Analysis Reporting System, 1982-1994.
Figure 9-10: United Nations, "World Resources 1994-1995, Oxford University Press, New York, 1994. Republished: "The Population of the United States".
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