| Chapter 3||
The primary safety issue facing older drivers is how to
adapt driving practices to accommodate declining
functional capabilities while still maintaining necessary
mobility. NHTSA's research agenda focuses on identifying
those capabilities that are critical to safety, determining the
driving practices that are appropriate for those capabilities,
developing information for assisting individuals in making
the proper choices, and cultivating licensing and
enforcement policies that protect public safety while
maintaining the mobility of older drivers.
BR> In contrast to the research needs of younger drivers, the research needed to ensure the safety and mobility of older drivers has been well defined. This chapter includes a brief description of the Agency's previous research and programmatic activities and specifies the direction of future research on older drivers.
NHTSA has had a research interest in the safety of older
drivers for many years. The Agency initiated a series of
projects in the mid-1970's to improve the safety of older
drivers. These projects focused on identifying the
problems of older drivers, with an emphasis on attempting
to understand the role of declining health and ways to
inform older drivers and assess their driving capabilities.
|Medical Limitations||In the early 1980's, NHTSA sponsored an in-depth study of
heart-attack victims that found, contrary to expectation,
that those with myocardial infarction actually had a better
safety record than their age, sex, and regionally-matched
controls. The study also indicated that very few of those
who had a heart attack reported it on their driver license
application at time of renewal.
Agency research also investigated potential improvements in the assessment of driver visual capabilities. This research identified a number of complex visual problems related to safe driving performance. Unfortunately, due to the nature of the tests and limitations of the technology available at that time, tests of these complex visual skills were not sufficiently reliable to establish new vision standards. This research provided evidence that most common visual problems, such as poor visual acuity, appeared not to have an adverse affect on driving safety. Most drivers suffering from poor acuity are aware of their problems and may adapt their driving accordingly.
BR> While certain medical conditions are apparent to those that contract them, others are not. Drivers with conditions in the former group seem to adapt their driving habits appropriately. However, individuals suffering from conditions in the latter group seem not to adjust their driving to compensate for their declining capabilities. These conditions include dementias and certain other cognitive problems involving attending to simultaneous events.
More than a decade ago, the Agency developed profiles of
older-driver crashes and recommended licensing practices
for older drivers. Working with the American Association
of Motor Vehicle Administrators (AAMVA), NHTSA
developed a series of guidelines designed to assist the
States in dealing with an array of driving problems.
Among the guidelines were those that dealt with functional
ability, certification of license examiners and a model
driver screening and evaluation program. These programs
were based upon what practitioners and the research
consultants thought were the best available practices.
Unfortunately, basic epidemiological data needed to
develop the policy guidelines did not exist at that time.
The Agency worked with the private sector to develop and
evaluate retraining programs for mature drivers. Driver
licensing research led to development of a driver manual to
help older drivers become familiar with and take
appropriate action about their declining capabilities. Older
people did accept, learn and retain the written information.
However, an evaluation of the crash and violation records
of those receiving the information failed to show any
significant reduction when compared with a control group.
The Agency developed and distributed special informational materials on occupant protection for older drivers, studied how older persons obtain information, and identified potential distributors of safety information to older drivers and pedestrians.
|Scientific Knowledge Base||
NHTSA staff were actively involved with the
Transportation Research Board (TRB) study on
Transportation in an Aging Society: Improving Mobility
and Safety for Older Persons, Special Report 218.
NHTSA's most recent research efforts on behalf of the older driver stem from the Agency's 1988 Traffic Safety Plan for Older Persons, published in response to the recommendations of the TRB report on aging. This plan outlines a number of research and development activities spread across several areas, including problem identification, occupant protection, driver licensing, pedestrians, consumer information, crash avoidance, and crashworthiness.
Following the Plan, the Agency conducted a number of research, development, and outreach activities. In order to complete the intended problem-identification objectives, Agency staff conducted an extensive literature review on aging and driving and an analysis of existing national data.
In 1989, the Agency convened a conference to establish a benchmark on current knowledge about aging and driving performance in order to define the research and developments needed to improve the safety and mobility of older drivers. This conference, cosponsored by the National Institute on Aging (NIA), the Federal Highway Administration (FHWA), and the Centers for Disease Control (CDC), was attended by more than 200 internationally known gerontological specialists in medical and behavioral research and applications.
Following one of the recommendations of the conference attendees, Agency staff were instrumental in establishing a TRB Task Force on the safety and mobility of older drivers. The purpose of this ongoing task force is to provide a forum for discussing older-driver research issues by individuals representing diverse disciplines and developing a coordinated set of research problem statements for the use of Federal and State government agencies and private-sector organizations. This Task Force co-sponsored a conference on assessing driver competency.
In 1989 and 1991, NHTSA established interagency agreements with the NIA. NIA had funded a group of longitudinal studies of functional abilities of older persons. The interagency agreement permitted NHTSA to obtain driving information from older persons in two of their study sites, rural Iowa and New Haven, Connecticut. This teamwork permitted the investigation of the role of older drivers' medical conditions and functional ability in their driving safety and personal mobility. This research has led to a much better understanding of the changing driving patterns associated with medical conditions and functional limitations.
|What We Know||
The research with NIA confirms earlier hypotheses that
most older drivers seem to be taking appropriate steps in
controlling when and where they drive based upon their
declining capabilities. However, there appears to be
certain groups of older drivers who do not appropriately
limit their driving because they are unaware of their
declining capabilities. Drivers in this latter group are especially difficult to identify, as the procedures currently
necessary to detect the medical conditions thought to be
associated with driving problems are time consuming,
complex, and expensive. Simple methods proposed to
regulate problem older drivers also tend to place
unnecessary limitations on drivers who do not pose safety
It also appears that older women are much more likely to stop driving than are men of the same age, and they give "lack of confidence" as their main reason for quitting. Results indicate that it is much easier to predict when an individual is likely to stop driving voluntarily than it is to predict their involvement with traffic violations.
This section describes NHTSA's research program for
addressing safety problems unique to older drivers. It does
not address the Agency's research on older vehicle
occupants or pedestrians.
|Problem Identification||Much of what we need to do is to understand the changes
that occur with aging as they relate to driving and provide
information to drivers to allow them to evaluate those
changes. The following research projects are necessary to
obtain fundamental information required to develop
|Establish Crash Risk for Various Medical/Functional||Sufficient epidemiologic data now exist to begin to establish statistical relationships between some medical
conditions and driving problems. Accordingly, this
research effort will determine the conditions under which
older drivers pose a threat to public safety and thus need to
be identified and controlled. This study will establish the
statistical link between crash risk, moving violations, and
various physical and mental conditions. It will also
identify the extent to which individuals with conditions that
affect driving performance correctly modify their behavior
and drive safely. The results of this study will serve as a
basis for developing informational, licensing, and
|Determine the Conditions Under Which Driving by Older Persons Should be Regulated||
Recent literature indicates that most older drivers
compensate for their limitations in what appears to be an
appropriate manner. A major function of law-enforcement
and driver-licensing agencies will be to identify and
regulate those drivers who do not self-regulate, i.e., those
who continue to drive in situations in which they pose
safety risks. To assist licensing agencies in establishing
appropriate regulatory approaches, the Agency will
determine the characteristics of drivers that do not
adequately self-regulate and the conditions, if any, under
which they may be able to drive while preserving safety.
|Document Mobility Consequences of Giving Up Driving||
Many States are reluctant to take away or even restrict
licenses of older drivers, particularly those who live in
rural areas, because there may be no transportation
alternatives. Societal problems are likely to arise if these
people cannot get around. Some key issues are whether
communities have the resources to supply specialized
transportation to older drivers who lose their licenses and
whether these older people are willing to use transit
systems in light of limited service and concern for personal
safety. In cooperation with the Federal Transit
Administration and the Administration on Aging, this
research will document a broad array of concerns of older
people and prepare a checklist to permit community
planners to assess the degree to which there are remedies
for these concerns within their community.
|Improving Understanding of Vehicle Crashworthiness for Older Occupants||
The increased frailty of older persons in crashes raises the
question whether increased levels of protection can be
obtained with improved vehicle or safety-systems design.
As part of crashworthiness research, NHTSA will analyze
crash data to determine the nature of injuries older persons
sustain due to restraint systems (lap/shoulder, airbag, etc),
compared to injuries sustained by younger people. Since
older drivers are more likely to be involved in side impact
crashes, these crashes will be investigated to determine the
extent to which older occupants are over-involved in fatal
|Identify Causes of Older-Driver Crashes at Intersections||This research will investigate the causes of older-driver
crashes at intersections, particularly those involving left
turns. Depending on the outcome of these analyses, this
will serve as a basis for developing either new advanced-technology
in-vehicle devices to assist the driver or
training and informational materials for drivers.
|Identify Barriers to Physician Referral of Patients for License Reexamination||In most States, laws require physicians to report patients
whose medical conditions may make them unsafe drivers.
However, there are marked differences in the laws and
practices of different States. Different State laws, such as
those requiring reporting certain conditions or providing
immunity to those reporting, undoubtedly affect the rate of
reporting unsafe drivers. This study will investigate the
legal, ethical and practical barriers to effective reporting by
physicians and explore the relationship between improving
safety and improving reporting requirements by physicians.
This study will include an investigation of the actual
influence on safety and mobility in States with different
|Identify the practical problems in family/friend reporting of functionally limited drivers||
There are marked differences across the States in laws
requiring families and friends to report a potentially unsafe
driver to the licensing agency for reexamination. At least
one State does not permit reporting, and others require that
individuals called in for reexamination be given the name
of the individual reporting them. This study will examine
the influence of these differences and recommend steps for
improving the process.
The following research projects focus on developing
strategies for addressing problem areas and generating
suitable countermeasure elements to address specific
|Develop Performance Assessment Techniques||
Current DMV tests do not detect the conditions that appear
to be most problematic. Detecting problem older drivers
will require testing for different capabilities under different
conditions than are currently in use. Performance tests that
closely approximate the driving situations of older drivers
and their functional limitations will be developed and
validated. Performance tests will also be developed and
validated for rehabilitation specialists, particularly in the
areas of dementia and perceptual difficulties associated
with split-attention tasks.
Many of the functional difficulties that potentially interfere with safe driving are brought about by medical incidents. Testing individuals with limitations from these medical events requires more extensive and complex procedures. Accordingly, performance tests will be designed for those professionals most able to perform the diagnostic testing and training.
|Develop Strategies for Meeting Mobility Needs of Older Former Drivers||
In cooperation with the Federal Transit Administration and
the Administration on Aging, this research will develop
strategies for meeting the transportation requirements of
older people who can no longer drive. Recognizing that
the transportation infrastructures in different communities
may be vastly dissimilar, this effort will design
informational packages, training materials, program
descriptions and guidelines for use at the State and
|Develop Improved Intersection Negotiating Practices||
Based upon in-depth analyses of the problem, NHTSA will
develop either behavioral or human-factor solutions to
improving intersection negotiation. The behavioral
alternative will develop assessment, informational, and
training programs designed to overcome some of the
current limitations. The other alternative will apply
advanced technology solutions, such as Intelligent Vehicle-Highway
Systems (IVHS), to these problems.
|Develop Empirical Guidelines for Medical Practitioners||
Current medical guidelines for advising older persons
about continuing driving are largely based on best
professional judgment rather than empirical data relating
conditions to safety problems. There is some evidence that
existing guidelines may unnecessarily restrict mobility.
This research will develop practical guidelines for
physicians, based on ongoing NHTSA epidemiological
|Develop Guidelines for Assisting Older Drivers in Making Decisions About Driving||
Following the development of appropriate assessment
procedures based on the Agency's epidemiological
research, NHTSA will develop a series of guidelines to aid
the process of identifying problem older drivers and
assisting them to make appropriate decisions regarding
driving. Guidelines for older people themselves will
provide "self-test" procedures that they may use to
determine the extent to which they should limit their
driving. Guidelines for families and caregivers will
provide methods for dealing with the older driver and for
discretely informing the licensing agency of the need to re-examine
the functionally-impaired driver. Guidelines for
police officers will address the need to report problem
drivers and provide methods for identifying drivers who
display symptoms of functional limitations or medical
conditions that may make them unsafe on the road.
|Develop Training and Informational Programs||
With the expected increase in the number of older drivers,
many of whom will have declining functional capabilities,
the Agency will focus on developing new ways of
improving their driving. For example, rehabilitation
specialists have been teaching stroke patients, head-injured
patients, and others to drive again. This study will identify
and examine existing training programs to determine the
extent to which they actually reduce crashes and help those
who should correctly reduce or eliminate their driving.
With new technology available, and better understanding
of the role of functional limitations on driving, there may
be new possibilities to improve both individual and group
training of older and functionally impaired drivers. The
study will document methods useful for retraining older
drivers, recommend improvements to existing programs,
and develop model procedures for use in retraining older
This effort will identify conventional and advanced
technology vehicle design features to prevent crashes
typical of older drivers. The potential role of advanced
technology to extend the driving careers of older people still needs to be identified. Devices and systems that may
aid younger drivers may not aid older drivers, and may, in
fact, be detrimental to their driving performance. Studies
of advanced technology will ensure that proposed systems
do not inadvertently degrade older driver safety and
performance by overloading their decision-making or
The following research projects examine existing programs
to document their implementation processes or assess the
extent to which they meet their outcome objectives.
|Evaluate Safety Benefit of License Re-examination Requirements||
Currently, there is lack of agreement on the necessity for
the licensing agency to require older drivers, particularly
those with clean records, to come to the agency for license
renewal. Most older drivers prefer to judge for themselves,
or have their physician or family aid them in deciding
when, where, or whether they should drive. Many
legislators and licensing administrators believe that it is
necessary to have older drivers renew in-person so that
their behavior can be observed to determine if they need to
be examined further. This research will evaluate the
outcomes of these alternative licensing procedures.
|Evaluate NHTSA/AAMVA Model Driver Screening and Evaluation Program||
Many States are eager to institutionalize methods to deal
with older drivers. NHTSA's Model Driver Screening and
Evaluation Program provides a set of guidelines for
consideration and adoption by State motor vehicle
administrators. Many of the actions recommended in this
program appear to duplicate the actions of self-regulating
older drivers. The extent to which this program can detect
problem drivers is unknown. This research effort will
document implementation procedures and evaluate the
safety consequences of the model program.
|Evaluate Safety Outcomes of Self/Community Appraisal of Driving Limitations||
To the extent that older drivers regulate their driving to fit
their declining capabilities, the driver-licensing system
serves as a back-up system or safety net. Under this
supposition, the main function of licensing would be to
ensure that drivers who continue to drive in situations
beyond their capabilities are identified, tested, and, if it is
reasonable to do so, licensed for appropriate restricted
The focus of the Agency's research and development effort is to produce guidelines for older drivers, their families, and caregivers to facilitate self-regulation of driving. The more effective these guidelines are in accomplishing their objectives, the more the licensing system functions in its back-up mode. This may result in the need to shift emphasis areas within licensing agencies.
This evaluation will follow the development of the Agency's guidelines and will assess their impact on older-driver safety. This effort will evaluate the guidelines' potential for correctly changing the driving actions of functionally-limited older drivers and determine the subsequent effects of increased self-regulation of older drivers on the roles played by driver-licensing agencies.
|Evaluate Programs to Maintain Mobility of Former Drivers||
Making the transition from driver to rider status for older
persons is not easy. Current programs must be evaluated to
help ensure that older people who no longer drive can
continue to meet their transportation requirements.
NHTSA, FHWA, the Federal Transit Administration, the
Administration on Aging, and the National Institute on
Aging have jointly proposed programs to address the
mobility needs of these former drivers. This effort will
evaluate such programs to ensure that they meet the needs
of the senior citizen.
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