Appendix 1
LITERATURE REVIEW

The purpose of the literature review was to provide a brief overview of some of the relevant literature that has been useful in identifying possible research and implementation problem statements. A full, comprehensive review of all of the relevant topic areas was not attempted. Those who wish a more detailed review are directed to the proceedings of the November 1999 meeting, when they become available.

Much of the information reported here was drawn from the reviews produced by participants of the November 1999 meeting. Many of these were “working papers” and, as such, they lacked reference lists, tables, and/or figures. Some of these reviews were drafts marked “DO NOT CITE”, “DO NOT QUOTE” “FOR DISCUSSION ONLY”, etc., and were to be used only for background information. Accordingly, this information is discussed but not cited directly in the discussion that follows.

In the discussion that follows, the following general topic areas have been briefly addressed:

THE AT-RISK POPULATION

Older Drivers

Crash rates of older drivers have been exhaustively reviewed and will not be repeated here in detail. Older drivers have low crash rates per capita. When exposure is taken into account, however, older drivers have higher crash rates than any other group except for teenagers. Because of this, older drivers have been the focus of important research efforts.

Defining the “Older” Adult

It is clear that the definition of “older” varies considerably. In one study, “middle-aged drivers” were ages 25-65, while “older drivers” were those over 65. In another study, the entire “older” sample consisted of drivers between 60 and 65. A 62-year-old driver, then, might have been classified as “middle aged” by one study and “older” by another. This inconsistency is understandable, given that certain difficulties (e.g., vision problems) can typically begin at fairly young ages, while crash rates do not rise dramatically until older ages. However, the literature as a whole might be well-served by a more consistent definition of “older.”

Characteristics of Older Drivers and Older Pedestrians

The population of Americans over 65 will grow dramatically in the coming years, both in absolute numbers and in proportion to the rest of the population. A majority of them will be female, given that men tend to die younger than women (see Wallace & Franc, 1999). Concurrently, the proportion of these seniors who are non-white will also increase. A recent review emphasizes the need to recognize racial and ethnic differences in travel patterns. White seniors tend to make more trips than seniors of color, and are less likely to use public transportation. Many older drivers have made no plans for alternatives to driving. Many of those who have thought about alternatives expect to rely on friends and family for transportation. Elders who live alone, have no close family, and have less money will be at a disadvantage when they stop driving.

The current characteristics of older adults may not adequately predict the behavior of older adults in 20 years. Cohort effects may strongly impact the expectations and behavior of the currently-aging population. That is, the baby boom generation may not behave the same way at age 70 that current 70-year-olds behave. Baby boomers may not accept authority as easily as the current older generation (e.g., may not accept a doctor’s advice to stop driving) and, as suggested by Sterns, Sterns, Aizenberg, and Anapolle (1997), baby boomers may be more likely to engage in high-risk behavior.

On the other hand, baby boom women are more likely than their older counterparts to have driven since youth; may be more experienced with high-density traffic, fast speeds, and complicated traffic patterns; and may have more experience overall (see Hakamies-Blomqvist, in preparation).

“Older” and “At-Risk” Are Not Synonyms

In recent years, researchers have refocused their efforts from “older drivers” to those at risk. It is important to remember that although the prevalence of driving difficulties increases with age, “at-risk” and “older” are not synonymous. Visual, cognitive, and physical problems can occur at any age and complicate the driving task. Similarly, old age alone does not necessarily indicate the presence of any of the characteristic “older driver” problems (Transportation Research Board, 1988).

AT-RISK DRIVERS AND CRASHES

When evaluating at-fault crashes, fault is generally assigned by the law enforcement officer who responds to the crash. The responding officer must often sort through conflicting statements and determine the cause of the crash. Because of the strong cultural bias against older drivers, it is possible that fault may sometimes be inaccurately assigned to an older driver involved in a crash. Thus, caution must be used when examining at-fault crash data.

That said, older drivers are involved disproportionately in right-angle crashes and in those involving a complicated maneuver. Specifically, older drivers are more likely to experience crashes at intersections (particularly while turning left across traffic) and while merging, exiting, or changing lanes on a limited-access highway. Older drivers are more likely to be cited for failure to yield right-of-way (Staplin & Lyles, 1991).

Older drivers are also often reported to be disproportionately represented in fatal crashes, and that proportion has increased since 1986 (Hakamies-Blomqvist, in preparation). Although that finding is often interpreted to mean that older drivers are worse drivers, Hakamies-Blomqvist (in preparation) reviews Maycock’s 1997 assertion that much of the overrepresentation is due to the “frailty bias”. That is, crashes involving older drivers are more likely to end up in the “fatality” category simply because older drivers are frail and more likely to be killed in a given crash than a younger person. Although the overrepresentation still exists, the curve flattens out considerably when the frailty bias is taken into account.

SENSORY/PERCEPTUAL PROBLEMS

Aging is associated with multiple changes in sensory and perceptual capabilities. A very brief summary of some these changes follows.

Vision

Aging frequently is associated with a number of changes to vision (see Owsley, in preparation; and Staplin, Lococo, McKnight, McKnight & Odenheimer, 1998 for reviews). These include thickening of the lens of the eye, which can interfere with close-up acuity and slow the process of refocusing on more distant targets. The lens also tends to yellow with age, which can reduce color perception. The formation of cataracts causes a decline in acuity and greater vulnerability to glare. Changes in the retina cause problems, and macular degeneration can destroy central vision. Glaucoma reduces peripheral vision. Spatial vision declines with age, as do static acuity and dynamic visual acuity. The prevalence of all these problems increases with age.

The relationships between various visual measures and crashes are mixed (see Owsley, in preparation, for a review). For example, the presence of monocularity does not reliably predict performance. And although it seems obvious that acuity is necessary for driving, static acuity in general has not been reliably predictive of crashes. Drivers may compensate well for a loss of acuity, or it may be that a restriction of range is involved: because static acuity is a requirement for licensure, drivers with very poor vision lose their licenses. Culturally, the need for acuity is very well-accepted, so it may also be that drivers self-regulate (restrict or cease) their driving when acuity is compromised - more than they would for other risk factors (e.g., restricted neck motion).

More reliably, glaucoma, cataracts, and declines in contrast sensitivity are related to at-fault crashes. Severe decreases in visual field are also related to at-fault crashes (Owsley, in preparation; Staplin et al., 1998).

Diabetic retinopathy is a difficult issue to address. Although it may be related to crashes, diabetic retinopathy is of course confounded with diabetes itself. Because the disease can have other effects impacting on driving, it is difficult to isolate the effect of diabetic retinopathy. Specifically, the severity of the disease, the individual patient’s level of control, the frequency of hypoglycemic reactions and their accompanying cognitive deficits, other complications (e.g., loss of sensitivity in extremities, cardiovascular damage, high blood pressure) and effects of medication can all complicate the study of diabetic retinopathy and crashes.

Depth Perception

Perception of angular motion declines with age, and appears to be related to a decline in neural mechanisms caused by aging rather than a particular pathology (see Staplin et al., 1998). Compared to younger drivers, older drivers inaccurately estimate approaching vehicle speeds. This effect may be strongly related to the overrepresentation of older drivers in crashes when turning left across traffic, and when changing lanes or merging/exiting on limited access roads. When determining gap acceptance, older drivers tend to use the distance of the approaching vehicle, rather than the speed of the approaching vehicle. This leaves them vulnerable to crashes with vehicles traveling faster than the stream of traffic.

Visual Attention

The driving task places complex demands on visual and cognitive processing skills. The Useful Field of View (UFOV) test measures selective and divided attention and is therefore a measure of both visual status and visual information processing. The UFOV test measures the visual field area over which one can use rapidly presented information. Reductions in UFOV are associated with at-fault crash involvement (see Owsley, in preparation, for a review) and with simulator performance (Walker, Sedney & Mast, 1992; as reviewed by Staplin, 1998).

The UFOV test is expensive and requires administration by a health care professional (Ball & Owsley, 1991). Because of these limitations, the instrument is unlikely to be useful as a licensing screen.

COGNITIVE CHALLENGES

Memory

Types of Memory

Traditionally, memory has been conceptualized as having three aspects: sensory (iconic/echoic) memory, short-term (primary) memory, and long-term (secondary) memory. These have typically dealt with memory as a storage function. As reviewed by Staplin (1998), older adults are more susceptible to iconic interference from distraction, and their iconic memory tends to be briefer than for younger adults. Short-term memory does not show reliable age effects, with the usual capacity of 7± 2 being a robust finding (e.g., Miller, 1963). Long-term memory, however, is vulnerable to age deficits, particularly in free-recall paradigms (e.g., Craik, 1977).

Working Memory

More recently, the concept of working memory has become a useful way of understanding immediate processing of information (Anderson, 1993). Working memory is thought of not simply as a storage function, but also as a stage where information is processed. It is helpful to think of working memory as the immediate, short term processing and storage area, where moment-by-moment cognitive operations occur. Therefore, the concept of working memory includes both short-term memory AND immediate processing functions. Working memory is not an infinite resource and has capacity limitations (Just and Carpenter, 1992).

Older adults exhibit slower processing of information than younger adults (see review, Staplin, 1998). As a result, working memory as a whole is not as efficient. Particularly, older adults show deficits in processing spatial information. Because the driving task places great demands on working memory (including spatial processing), working memory deficits are likely to strongly impact the driving task.

Reduced working memory capacity may be amenable to corrective design practices. Advance signing intended to remind drivers of a decisional rule (LEFT TURN MUST YIELD ON GREEN Ž) resulted in improved maneuver decision responses for older drivers (Staplin and Fisk, 1991).

Modifications designed to lessen demands on working memory (e.g., advance signing for TCDs/mid-block street signing) for older drivers may also benefit young, inexperienced drivers. Inexperienced drivers have not yet automatized the driving task and must devote attentional capacity to basic activities such as lane-keeping. The same modifications intended to compensate for older drivers’ reduced working memory may also compensate for inexperienced drivers’ overloaded capacities.

Attention

Attention-Switching

One capacity important to driving is the ability to quickly reorient attention to relevant stimuli (Kahneman, Ben-Ishai & Lotan, 1973). For example, drivers must be able to quickly transfer attention to a potential threat. Both visual (Avolio, Alexander, Barrett & Sterns, 1981) and auditory (Gopher & Kahneman, 1971) measures of attention-switching have demonstrated an association between this ability and reduced crash risk (Kahneman et al., 1973; Avolio et al., 1981, Mihal & Barrett, 1976; cf. McKenna, Duncan & Brown, 1986).

Divided Attention

Drivers also need to be able to attend to multiple stimuli when driving. For example, drivers must concurrently control the vehicle, monitor other vehicles and pedestrians, read signs, and navigate toward their destination. The ability to divide attention among competing stimuli is a critical process. Older drivers show a decreased ability to divide attention (see review, Staplin, 1998). It appears that this may be at least partly due to a reduced efficiency in the visual search process, which is especially affected by age.

Dementia

Dementia occurs when there is a progressive loss of cognitive function. It is characterized by impairments in memory, abstract thinking, judgment, and/or personality change. The different types of dementia are covered well elsewhere and will not be reviewed here.

Dementia increases with age, as do the overall prevalence of conditions associated with reduced cognitive function (e.g., Alzheimer’s Disease, strokes, Parkinson’s Disease, diabetes, cardiovascular damage, and side effects of medication). Demented drivers have higher crash rates, particularly when the dementia is severe. Complicating the picture, dementia sufferers are notoriously poor at self-evaluation and often do not realize the extent of their impairment. However, a diagnosis of dementia alone does not appear to be a good basis for license revocation. Instead, severity might be a more reasonable basis for restricting or revoking licensure.

PHYSICAL AND PSYCHOMOTOR ABILITIES

Reaction Times

Findings regarding older drivers’ perception-reaction times are mixed. In general, older adults’ responses are believed to be slower. Yet in certain well-learned tasks, older adults show no deficits.

This conflict may be resolved in two ways: first, by the often-reported finding that older adults show excellent crystallized knowledge and abilities, but have deficits in fluid knowledge and abilities (e.g., Lezak, 1981). That is, older adults tend to recall established facts and procedures very well, but may have difficulty manipulating information and responding in unfamiliar ways. This is true on very low level as well as higher-level tasks: older adults often show no deficits in simple button-press reaction time studies, but are slower in decision reaction time tasks. On a higher level, older adults perform well on rote tasks but have difficulty generating new responses.

Congruent with this, Knoblauch, Nitzburg and Seifert (1995) found that older drivers had problems with areas such as toll plazas where the correct course of action was unclear: the lack of guides such as lane lines and the unpredictability of other vehicles caused particular difficulties for older drivers. In addition, older drivers listed unfamiliar locations and unexpected traffic patterns as causing problems. It appears that fluid driving responses are especially difficult for older drivers.

The second solution to the puzzle lies in the cumulative effect of small differences in response times. The combination of slowed cognitive processing and slowed motor responses causes a decrement in speed of psychomotor responses. For example, the series of events required to detect a hazard, decide on a response, initiate and execute the response (or series of responses) are quite complex. A very small delay in each of the steps results in a significant slowing overall (e.g., Staplin, Lococo & Sim, 1990; as reviewed by Staplin et al., 1998).

In addition, older drivers take longer to react when they have time to do so, even in a simple task. Knoblauch, Nitzburg, Reinfurt, Council, Zegeer and Popkin (1995) found that some older drivers, when far from the onset of an amber signal, took longer to decelerate than younger drivers. When close to the signal at the onset of the amber phase, older drivers responded no differently than younger ones. It appears that older drivers’ slower responses were not necessarily inappropriate, and not necessarily uncontrollable.

Motor Responses

In older adults, movements are made more slowly and are less coordinated (see Staplin, 1998, for a review). Head and neck mobility may be compromised, particularly when arthritis is present. This may negatively affect drivers’ ability to check blind spots, look to the rear of the car, and quickly turn their heads to redirect visual attention. Some movement problems, however, are improved by exercise and so may be correctable, at least to some degree.

Physical Risk Factors

As reviewed by Marottoli (1996), several physical conditions may raise crash risk. These include cardiovascular disease, sleep apnea, chronic pulmonary disease, cerebrovascular conditions (e.g., strokes), diabetes (particularly during hypoglycemic reactions), arthritis, and side effects of medications. These conditions are likely to cause difficulties with the driving task.

Diller, Cook, Leonard, Reading, Dean and Vernon (1999) reviewed the crash records in Utah of restricted and unrestricted drivers with medical conditions. They found that drivers with medical conditions (both restricted and unrestricted) had higher crash and at-fault crash rates than comparison groups. It seems clear that many medical conditions are associated with increased crash and at-fault crash rates.

ERRORS COMMITTED BY OLDER DRIVERS

Unsafe driving practices have been extensively documented (see McKnight & Stewart, 1990; McKnight & Urquijo, 1993; and Malfetti & Winter, 1987). In general, mistakes made by older drivers tend to include inadequate search & scan, difficulties in lane keeping, incorrect vehicle positioning for turns (including both lane selection and lane-keeping), inappropriate or delayed stopping, unsignaled lane changes, and failing to respond appropriately to road signs or signals.

OLDER PEDESTRIANS

Although there is far less research on older pedestrians, it is crucial to remember that the findings of reduced visual, cognitive and physical abilities have implications for older pedestrians as well as drivers. Although pedestrians do not pilot vehicles, they are required to deal with the same demanding environment that drivers must navigate. For example, when crossing a street, pedestrians must determine gap acceptability, predict vehicle trajectories, make decisions and execute an ambulatory maneuver. At a busy intersection, they have as challenging a task as a driver who wishes to execute a left turn across traffic, but do not have the visibility or the physical protection of a vehicle. Kerschner & Aizenberg (1999) found that older pedestrians indicate that they are concerned about safety, inadequate timing of traffic signals, poor road conditions, and cars turning right on red.

In addition, older pedestrians may constitute a more impaired population than older drivers. When an older driver accumulates evidence of impairment and decides to cease driving, he or she may often become a pedestrian, particularly in urban areas. As a result, older pedestrians may include those who no longer have the visual, cognitive and/or motor responses necessary for driving.

Very little is known about older pedestrian crash risk and exposure in the U. S. In Victoria, Australia, Fildes (1997) found that, if adjusted solely for difference in population numbers, older people were overrepresented in fatality and injury pedestrian crashes. This, however, does not adjust for time or distance spent walking. Almost nothing is known regarding fault of older pedestrian crashes. Knoblauch et al. (1995) reported that about a third of deaths of pedestrians over age 65 occurred at intersections.

ADAPTIVE STRATEGIES

Older drivers often adapt quite well to their changing capabilities. Older drivers show less optimistic and self-serving biases than younger drivers and often are aware that they are less versatile in unexpected situations: they acknowledge an increased likelihood of an accident compared to younger drivers (Holland, 1993). Older drivers generally perceive risk or hazard to be higher than younger drivers do (Lerner, Williams & Sedney, 1988; Raymond, Seifert, Nitzburg, McKnight, Tippetts, & Knoblauch, 1999). On a more detailed level, older drivers correctly perceive that crash risk is higher at intersections (Lerner et al., 1988) and that crash risk or hazard are higher when merging or exiting on a limited-access roadway (Lerner et al., 1988; Raymond et al., 1999).

In a recent review, Smiley (in preparation) utilizes Michon’s (1985) framework of three levels of behavior: strategic (high-level decisions ), tactical (moment-to moment decisions such as speed choice), and operational (second-to-second behavior, which is often highly automatized). Smiley categorized older drivers’ adaptations within this framework and showed that older drivers are most able to affect their strategic and tactical decisions, but have difficulty in changing their operational behavior. That is, older drivers can choose to live close to their destinations (a strategic behavior that is fairly rare); they can and do make strategic changes such as reducing both their overall exposure and their higher-risk exposure (such as bad-weather and night driving),and they are less likely to drink and drive. On the tactical level, older drivers choose lower speeds, allow longer headway, and wait for larger (longer distance) gaps. Operational behaviors, however, are difficult to affect due to their automaticity.

In general, older drivers tend to reduce their exposure by driving less and by avoiding driving in poor conditions (e.g., night, bad weather, rush hour, etc.) (Hakamies-Blomqvist, in preparation; Knoblauch et al., 1995). They drive more slowly, have more conservative gap acceptance, and are less likely to smoke or adjust the radio while driving (Hakamies-Blomqvist, in preparation).

Some adaptations are social in nature. Raymond et al. (1999) noted from focus groups that older couples sometimes direct and assist each other in driving. As one couple stated, “It takes both of us to drive.” Previous research has indicated that spouses use each other as external memory sources (see Wegner, Erber and Raymond, 1991). For driving, it is possible that older couples may use each other as external processing capacity as well. The passenger may often navigate, read signs, assist in hazard detection, and remind the driver of tasks. This adaptation may counteract some of the limitations posed by reduced working memory capacity.

PUBLIC INFORMATION & EDUCATION

Objectives

A social marketing campaign, according to Milton (in preparation), will attempt to accomplish the following: to help older people use techniques and behaviors that will allow them safe driving for as long as possible; to help with driving cessation; and to educate the public with accurate information about older drivers (rather than the occasional sensationalized incident).

Campaign Guidelines

Successful public education campaigns take the following into account, according to Kanouse (1988): information must specifically address the audience’s needs; it should give information the audience does not already have; it should take advantage of existing motivation (give them information that helps them do what they already wanted to do); it should empower the audience rather than making them feel helpless; it should contain information that is relevant to decisions; information should be provided in a way that takes into account the method and time of use (e.g., radio is an effective medium because it reaches people while they drive); it should help people reframe their thinking; and it should be presented repeatedly. A well-designed transportation PI&E effort will take these recommendations into account.

Reaching Professionals

As reviewed by Milton (in preparation), a Lifespan survey showed that professionals such as doctors, nurses, therapists, psychologists, and others seek information from motor vehicle departments, professional journals, professional societies, continuing education and conferences. They infrequently used media, experience, research, or state health departments. Efforts designed to reach these professionals should take this information into account.

Reaching Drivers and Their Families

State motor vehicle departments and health and social service agencies may be the fastest means of reaching older drivers and their families in an educational campaign, but efforts are most influential when they include local channels such as churches, senior centers, libraries, post offices, etc. (Milton, in preparation).

Recently, the state of New York has issued a publication aimed at families of older drivers (LePore, 2000). This handbook is a comprehensive guide for families dealing with driving cessation and covers a wide variety of topics, including the following: behaviors that indicate the driver is at risk; broaching the subject of driving cessation; interventions; reporting hazardous drivers; relevant agencies; adjustment to driving cessation; transportation alternatives; suggestions for extending the ability to drive safely; and advance planning for driving cessation.

AAA has also issued a handbook for friends and families of older drivers (AAA, 2000). Among other topics, it gives an overview of age-related changes, provides a brief assessment, suggests strategies to prolong safe driving, lists transportation alternatives, suggests interventions and provides information about reporting unsafe drivers.

DESIGN COUNTERMEASURES

As summarized by Staplin (in preparation), potential countermeasures can assist older drivers. Older drivers would be helped by a long list of recommendations. In general, these include redundant signing, increased contrast of markings, increased use of delineation and pavement markings, allowing greater margins for error (e.g., wider turn lanes, shoulders, lengthened perception-reaction time used by designers), lengthened WALK phase of pedestrian signals, and simplification/shortening of messages used in variable message signs. For a review of research supporting highway design modifications for older drivers, see the Proceedings of Transportation in an Aging Society: A Decade of Transportation Research Board (in preparation). For a full list of recommendations, please see the Federal Highway Administration’s Older Driver Highway Design Handbook. For example, increased contrast in signs and pavement markings can help older drivers at night. Adding delineation wherever possible (e.g., marking curbs themselves as well as having the edgeline on the road surface) would also help. For intersections, a number of modifications would improve older driver performance; for example, constructing roadways so that they meet at a 90-degree angle, allowing wide turn lanes and shoulders, lengthening the perception-reaction time used by designers, would assist older drivers.

DRIVING CESSATION

Self-regulation is an important aspect of driving for the older population. Many older adults continue to drive until very old, but very frequently reduce their risk by reducing their exposure and particularly their high-risk exposure (Hakamies-Blomqvist, 1994).

Many elders elect to stop driving because of failing eyesight, other medical problems, and the realization that they were driving unsafely (Kerschner & Aizenberg, 1999). However, many may not be aware of a decline in their abilities. Dobbs (1996) followed a sample of drivers who had failed a DMV assessment and were recommended to stop driving. Three quarters of the drivers said they had been unaware of their need to stop driving. The majority complied immediately. Twenty percent, however, disregarded the recommendation and continued to drive. Self-regulation cannot be solely relied upon. Many older adults dread the thought of losing their ability to drive and refuse to consider alternatives, according to recent reviews. When self-regulation fails, outside regulation must be considered.

SCREENING INSTRUMENTS

The Gross Impairments Screening (GRIMPS) attempts to detect impairments in critical functional abilities (rather than focusing on a particular medical diagnosis) (Staplin & Hunt, in preparation). It measures high and low contrast static visual acuity, intact scanning pattern, visualization/understanding of spatial relationships, visual search and sequencing, information processing speed, divided attention, attention switching, lower limb mobility, upper limb mobility, and head/neck flexibility. The GRIMPS test is currently under pilot testing in the state of Maryland.

A list of NHTSA-sponsored driver assessment programs nationwide can be found in Staplin & Hunt (in preparation), as can a list of state-by-state requirements for license renewal.

MOBILITY ALTERNATIVES

Non-driving modes of transportation can apply to any part of the population who does not drive. As summarized in “Mobility Alternatives for Seniors”, non-driving options include public transportation such as fixed route rail, bus, paratransit, community transportation (e.g., community bus), demand-responsive transit (e.g., dial-a-ride), flex-route, Independent Transportation Networks, volunteer services, taxis, bicycles or tricycles, hitchhiking, and walking.

Different capabilities are needed in order to utilize services; for example, a bus passenger must be able to get to the bus stop and board the bus. Therefore, the abilities of the individual determine what options he or she is able to use. In addition, potential users must have information about options available to them, and must be able to pay for services if needed. Further, several of the options can be difficult to use because of scheduling, eligibility restrictions, and limited capacity.

The geographical location of users determines their options as well. Urban dwellers have different options from rural dwellers (e.g., more access to traditional buses and trains). Despite having more options, city dwelling elders use public transportation relatively lightly (Suen, in preparation). This may be because of accessibility issues. It may also be because older adults feel more vulnerable to threats such as crime and bad weather - a young person may be cautious when waiting for a bus in the dark, but an elderly person may simply elect not to make the trip.

A framework of transportation options, information needs, costs, service providers, and necessary abilities of users is given in Suen (in preparation). As Kerschner & Aizenberg (1999) point out, older adults tend to look for transportation that fulfills the “Five A’s”: Availability, Accessibility, Affordability, Acceptability and Adaptability.

Most frequently, elders plan to obtain rides from someone with a private car, usually a friend, neighbor or daughter (Kerschner & Aizenberg, 1999). According to Freund (1996), the vast majority of these rely on a daughter. Unfortunately, the population of those who need care (and rides) is increasing faster than those who are available or willing to provide care (Wilson, 1994). The potentially-caregiving younger generation is frequently occupied with childrearing and can become quickly overextended. Caregivers are most likely to be daughters, but cultural changes are making many of those individuals unavailable for the task: adult children are increasingly likely to live far away, daughters are increasingly likely to hold full-time jobs and be unavailable during the day, and ever-decreasing family sizes reduce the pool of adult offspring able to give rides or other caregiving. Older adults are less and less able to rely on their children for day-to-day transportation.

As a recent review notes, housing patterns, land use and travel needs are geared toward car-based mobility. Without dramatic change, vulnerable, non-driving adults will be left with little access to social contact, necessary goods and services, and the outside world.

Appendix 2

Research Projects Suggested and Prioritized at the November, 1999 Meeting 
Included in Literature Review of Current Project
Title General Approach/ 
Type of Study
Desired Outcomes 
(Question to be Answered)
Lost Mobility: The Cost Cost analysis Quantify cost of loss of mobility on health care costs to society
Do Assessment and Retraining Programs Improve Driving? Evaluation Conduct follow-up of studies of outcomes of assessment and retraining programs, including qualification of remediation effectiveness
Services For Those Who Stop Driving PI&E Social marketing to older people so they know that they are eligible for services (and to design services that match their needs)
Evaluation of Transportation Solutions Evaluate existing programs Identify and evaluate successful transportation solutions developed in/by communities/local groups (mobility options)
Mobility for Older Adults: The Benefits Cost analysis Quantify social benefits and disbenefits of remaining mobile and connected to services (policy)
Screening Battery Development Development, Evaluation, Implementation Develop and evaluate, then implement, screening tests for visual, cognitive and/or physical problems related to crashes (and test training materials for administrators)
Self-regulation Focus groups, surveys How does older driver behavioral self-regulation adaptation develop?
Screening for Higher-Order Cognitive Functions Evaluation Develop predictive models through the identification of assessment tools that take into account the role of higher order functions (e.g., judgment) and level of expertise
Evaluation of Routine Screening Evaluation Determine benefits/disbenefits of routine screening of older drivers (use randomized controlled trials)
The Need for an “Older Adult” Crash Test Dummy Development Crash dummies
- criteria for older persons
- need separate dummy?
- user to examine interior components
A Guide for Planners Policy How to get transit-oriented development/mixed use zoning adopted
The Cost of Non-mobility Cost analysis What are economics of non-mobility to the individual, family and community?
Cost/Benefit of Highway Modifications Cost/benefit analysis Benefits/costs of treatments (highway)
Information on Mobility Alternatives PI&E Strategies to communicate mobility alternatives
Cooperation Between Interested Parties Liaison Develop more efficient linkages across agencies, professions, and others involved in older driver programs
Educational Efforts PI&E Development of overall public information strategy or social marketing plan
Assessment Accessibility Survey, focus groups, expert panel Identify barriers to seeking driver assessment-both self referrals and other referrals (e.g., physician)
Licensure Rates By Gender/Ethnicity Demographic study - archival Examine ethnic/gender differences in licensing rates for older persons
Summary of Knowledge Literature Review “Best practices”/lessons learned
Necessary and Discretionary Trips Focus groups, survey Better understanding of how older people define necessary and discretionary trips
Developing Mobility Alternatives Expert panel, focus groups Develop mobility alternatives for former and high-risk drivers
Policy Impact on Access & Mobility Patterns of Older Travelers Evaluation Evaluate impact of government policies (e.g., land use) on access and mobility patterns of older travelers (all modes)
Transportation Needs of the Elderly: Mobility patterns vs. Lifestyle Patterns Cost Analysis Determine magnitude of impact of lifestyle changes and mobility patterns of older persons on transportation needs
Evaluation of Mobility PI&E Resources Evaluate PI&E/
Expert Panel
Community-level evaluation of senior mobility examine materials/strategies for:
- appropriateness of messages and delivery system
- cultural and geographic appropriateness
- financial realities
Evaluation of Potential Improvements to Public Transport Expert Panel Study changes needed to improve transportation mobility rate, re: older population
Alternative Transportation Users: Needs And Capabilities Survey What are needs and capabilities of alternative transportation users, including pedestrians?
Identification of New Messages PI&E Identification of new messages - identify successful models for other social issues that can be adapted and tested for senior market
Assessment of Medication Effects on Older Drivers Expert Panel Medication (prescription and over the counter): What are the connections and implications for the older driver?
Impact of Federal Laws on State and Local Services Archival Study/Expert Panel How federal laws and regulations impact state/local services (e.g., jurisdictional, boundaries, etc.) (include effect on minorities)
Trips Not Taken: Cost and Willingness to Pay Cost Analysis Quantify trips not taken and willingness to pay for those trips/variety of means
Dynamic Sign Legibility Field Test Dynamic field Testing of highway sign legibility
Older Adults’ Transportation Needs: Case Studies Case Studies Comparative case studies on how older persons currently meet (or do not meet) transportation needs
Standardization of Training and Standards of Driver Rehab/Assessment Professionals Expert Panel Identify research issues involved in potential standardization of training and standards of driver rehab/assessment professionals
Evaluation of Older Driver Training Programs Evaluation Older person driver training effectiveness

Appendix 3

Implementation Projects Suggested and Prioritized 
at the November, 1999 Meeting
Included in Literature Review of Current Project
Title General Approach/ 
Type of Study
Desired Outcomes 
(Question to be Answered)
State of the Practice: Partnerships Between Entities State of the Practice: Best practices on public/private and interagency partnerships that have been established - emphasis on solutions to implementation barriers, financing, etc.
At-Risk Driver Assessment Tiers Screening/Assessment Development Develop multiple tiers of assessment (e.g., self assessment tools, education for medial/law personnel)
NTPS Survey - Further Analysis Analysis Further detailed analysis of NTPS survey for older population sample
Alternative Transportation: What’s Working, What’s Not Literature Review/Expert Panel Best practices report on establishing/resolving policy issues and creating funding mechanisms for alternative transportation
Tools for Self-Assessment Instrument Development Self assessment tools for different users
Training Programs: Strategies and Alternatives Archival/State of Practice Document classroom/on-road skills training programs which include information on alternative transportation options and adaptive strategies
Aging and Transportation Issues: Promoting Awareness PI&E Promote awareness and education on aging and transportation issues and solutions - include policymakers, consumers, professionals, service providers, health and medical, public community organizations
Screening Instruments and Crash Risk Evaluation/Validation Pilot test comprehensive screening and track crash experience of high risk vs. others
Effects of Medication on Driving PI&E Effective dissemination of existing knowledge (e.g., medication effects)
The Maryland Model: Further Testing Pilot Test Further pilot test MD at-risk program (test exportability)
Before You Give Up Your Keys: A Handbook of Options PI&E Pilot test program to make older drivers and families aware of options prior to loss of driving privilege
Creating Options for Non-Drivers PI&E Encourage states/communities to investigate, develop and promote alternative transportation solution to empower individuals to make informed mobility choices
Law Enforcement Program: Detecting Problem Drivers Curriculum Development Develop training programs for law enforcement to spot problem drivers - provide referral avenue - no age discrimination
Older Drivers in the 21st Century: Economic Opportunities PI&E Develop forceful statement of reality of situation to convince private industry that this is a positive economic issue
Functional Characteristics of the At-Risk Driver PI&E Develop functional descriptions of the problems
How to Talk with an At-Risk Driver Curriculum Development Provide training to enable caregivers to communicate effectively
Policy Regarding Older Drivers PI&E Develop and test messages directed toward policymakers

Appendix 4
Unprioritized General Research Concepts Suggested 
at the November, 1999 Meeting 
Included in Literature Review of Current Project

General Research Concepts

Appendix 5
Unprioritized General Implementation Concepts Suggested 
at the November, 1999 Meeting 
Included in Literature Review of Current Project

General Implementation Concepts

Appendix 6

Additional Research and Implementation Projects
Identified During the Review of Research and Materials
Title General Approach/ 
Type of Study
Desired Outcomes 
(Question to be Answered)
Older Drivers: Fault or Foul? Analyze hard-copy crash reports Do Older Drivers cause more crashes, or are they simply less able to adequately respond to traffic? (Are they at fault or just less able to avoid potential crashes caused by others?)
Crashes Involving Older Pedestrians Exposure study Are Older Pedestrians overrepresented in pedestrian crashes in the U. S.?
Guidelines for Physicians: Talking to the Older Driver PI&E Physicians often are expected (by patients and family) to discuss a patient’s ability to drive. Develop guidelines for physicians.
Is a Car Worth the Expense? PI&E Campaign showing relative cost of taxi vs. car when few trips are made.
Modifications for Older Pedestrians Expert Panel, cost-benefit analysis What existing pedestrian safety measures would most benefit Older Persons? (e.g., lighting, etc.)
PI&E Measures Nationwide: What Has Been Effective? Evaluation Evaluate success of existing materials and pinpoint the most productive lines to continue
Passengers of Older Drivers: Distraction or Assistant? Investigate performance of ODs with passengers, particularly spouses. Assess performance in simulator while unassisted/assisted by spouse. May compare to middle-age drivers and/or inexperienced drivers. Do older couples use each other as external working memory sources when driving? Unlike teens with passengers, ODs with spouse-passengers may have lower crash rate.
Inter-agency Cooperation Cooperate with NIDR to optimize transportation for those who do not drive
Defining “Older” for Researchers Review of literature to determine a reasonable, consistent definition of “older”. Expert Panel? At what age is a driver “older”?
Screening for Performance-Related Visual Problems Evaluation How can vision screening be improved? What current vision screening test is most predictive of crashes?
Screening for Cognitive Skills Literature review, Expert Panel, basic research How can cognitive abilities be assessed? What current screening test is most predictive of crashes?
Targeting At-Risk Populations for Screening Expert Panel, literature review On what basis should drivers be required to complete screening tests? Age? Medical referral? Insurance company referral? Crash status? Other criteria?
Insurance Companies as Gatekeepers: Referring At-Risk Drivers for Screening Liaison Explore cooperation with insurance companies - they can be gatekeepers.
Vehicle Adaptations for Older Drivers Product development Can vehicles be changed to accommodate the common physical impairments in older drivers?
Referring At-Risk Older Drivers Expert Panel Develop referral system for at-risk drivers
Medication Side Effects and the Driving Task Literature Review, expert panel of physicians What medications negatively affect driving ability, and are there alternatives?
Promoting Self-Regulation PI&E How can older drivers be encouraged to appropriately self-regulate?
Use of Public Transportation: Barriers and Solutions Focus groups, surveys Use of buses/subways by elders is relatively rare, even when they are available. Document reasons.
A Cost/Benefit Analysis of Promising Highway Enhancements Cost/benefit analysis Which modifications are most beneficial per dollar spent?
Rural Older Drivers, Crashes, and Exposure? Survey, crash analysis Do rural ODs continue to drive for longer because of lack of alternatives? If so, is this related to crashes?
Transportation Needs of Older Adults in Rural and Suburban Areas Cost analysis Generate a handbook for transportation planners
Pedestrian Safety: Implementing Current Knowledge at Intersections Expert panel Improve and implement current knowledge re: walking speed and comprehension of Walk/Don’t Walk signals
Edge Lines and Older Drivers Expert Panel/field study Do edge lines improve performance of older drivers?
Routes to Success: Maps for Older Drivers Feasibility study Develop maps/guides of routes that are friendlier to ODs (e.g., well-lit, good pavement markings, lower speed limits, etc.)
Routes to Success: Maps for Older Pedestrians Feasibility study Develop maps/guides of routes that are friendlier to older peds (e.g., well-lit, have crosswalks and ped signal, etc.)
RTOR Restrictions and Traffic Flow Traffic flow study Do RTOR restrictions affect traffic flow?
RTOR Restrictions and Comprehension Focus groups, paper & pencil Do drivers and ped understand RTOR restrictions (e.g., “no right on red when peds are present”)?
Safe Mobility: Priorities of Roadway Improvements for Older Adults Expert Panel Develop and prioritize implementation of improved infrastructure for ODs and Ops.
Older Women’s Transportation Needs: Rural and Urban Survey of geographically diverse cities & towns Older women’s transportation: needs and current use
At-Risk Women’s Safety Issues Focus Groups, Survey Older women’s safety Issues with public transportation
Car-Pooling Options for Older Working Women Workshop, Focus Group, PSA’s Feasibility of older women’s carpooling

Appendix 7

Additional Research Projects
Proposed by Expert Panel Members
Title General Approach/ 
Type of Study
Desired Outcomes 
(Question to be Answered)
Older Females’ Crash Risk: Disentangling Relationships   Examine higher crash rate for older females (gender-age interaction)
Medical Conditions: Lack of Insight for Self-Regulation Evaluate subjects - survey Are patients aware of effects of dementia, sleep apnea, hypoglycemia, medications?
Unlicensed Drivers   Keep unlicensed drivers off the road
Rate of At-Risk Status Use cohort studies Identify % of older drivers that are at-risk (or are unsafe to drive)
Age-Based Screening   Define age cutoff for screening - is there a change in curve?
Age and Risky Conditions   Define what age is associated with conditions which impair driving
Keeping Good Programs Alive   Sustainability of existing programs
Medical Advisory Boards   Role of medical advisory boards in relation to at-risk drivers - Series of standards to apply

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