David W. Eby

The relationship between self-regulation and driving-related abilities in older drivers: An exploratory study

Objectives. The objectives of this paper are to review the published research findings about the role of self-regulation in older driver safety and to report on an exploratory study to better understand the self-regulatory practices of older drivers as demonstrated through the avoidance of a number of specific driving situations including making left turns and driving alone, at night, in bad weather, in high traffic, and on the expressway and through restricting driving to familiar or local areas only. Methods. As part of a larger study on the development and testing of a self-screening instrument by older drivers, data on self-regulation were compared with data on driving-related abilities collected through clinical and on-road assessments for 68 drivers age 65 and older. Results. Findings indicate that 25% of subjects reported self-regulating their driving in some way. Of those who self-regulated, five individuals reported avoiding just one type of driving situation, six reported avoiding two, one reported avoiding three, and five reported avoiding four types of situations. The most frequently reported situations were avoiding driving at night (19.1%) in bad weather (8.8%), and driving only in local areas (13.2%). Women were considerably more likely than men to report self-regulatory practices. Consistent with the findings of low avoidance of driving situations, subjects generally reported high levels of confidence, with the exception of driving at night, for which over one third of women reported being “not at all confident.” Overall, subjects were least confident driving at night, in bad weather, and on expressways. Results from a logistic regression model indicate that subjects did appear to self-regulate their driving at night based on their performance on the on-road driving assessment (p < .01). That is, for every 10-unit decrease in driving score (with lower scores indicating poorer driving performance), subjects were 1.6 times more likely to self-regulate. Conclusions. Continuing research on the extent to which older drivers appropriately self-regulate their driving is warranted. Future studies should focus on objectively measuring self-regulation, possibly through instrumented vehicle studies, and comparing these measures with clinically determined functional abilities and driving performance. It is also important to take into account differences in self-regulation by sex, as well as the effects of confidence in driving ability and insight into functional impairments on self-regulation.

THE EFFECTS OF STANDARD ENFORCEMENT ON MICHIGAN SAFETY BELT USE

The purpose of this study was to assess the effects of standard enforcement legislation on safety belt use in Michigan through a series of seven statewide direct observation surveys. A secondary purpose of the study was to compare the results in Michigan to the results in other states that have changed the provision of their mandatory safety belt use law from secondary to standard enforcement. The study found that standard enforcement has been effective in increasing safety belt use in Michigan. Immediately following the implementation of standard enforcement, Michigans belt use rate increased to 83.5%, 13.4 percentage points higher than the highest rate previously observed. One year after the change, safety belt use in Michigan was still nearly 10 percentage points greater than the highest observed rate before standard enforcement legislation was enacted. Results indicated that safety belt use decreased slightly in the year following the implementation of standard enforcement. This appears to be an overall trend across all observed groups, and not due to any single demographic category. The results also suggest that standard enforcement legislation appears to have a greater effect on groups with historically low belt use, such as young people, males, passengers, and Black/African-Americans. When compared with other states that have made the change from secondary to standard enforcement, the increase in the safety belt use rate in Michigan was comparable to the increase seen in states with relatively high safety belt use prior to standard enforcement. However, states that had low safety belt use rates prior to adopting standard enforcement legislation observed a larger percentage point increase in the year following their change to standard enforcement.

A statewide analysis of child safety seat use and misuse in Michigan

This study was designed to determine frequency of child safety seat use for children under the age of 4 years in Michigan, as well as to determine types of misuse. No state has previously conducted such a statewide survey. A two-stage sampling plan was used with data collected through direct observation at a sample of 88 child-care centers and pediatric clinics throughout the state. Misuse data were collected at a subset of the sites through driver interview and visual and hands-on inspection. The study results indicate that 74.5% of children under 4 years of age in Michigan are in safety seats with use highest in vehicles driven by belted drivers, females, and drivers under 60 years of age. Some degree of seat misuse was found in 88.5% of the inspections. The most common types of misuse were related to snugness of fit (both in installing the seat into the vehicle and in securing the child), use of the safety belt locking clip, and the harness positioning clip. Drivers who had a high occurrence of misuse, as compared with drivers with lower misuse, had lower educational levels, removed the seat frequently from their vehicle, were not the parent of the child, and had children who were both younger and smaller. The results show that efforts to encourage people to use child safety seats have been successful.

Maintaining Safe Mobility in an Aging Society

This book addresses the complexities surrounding the rapidly expanding number of aging drivers and practical solutions for sustaining their safe transportation. In addition to discussing how age impacts both the risk and severity of crashes and the link between mobility and well-being, this book discusses means to achieve safer mobility, including roadway design and community transportation options. Authored by driver safety and awareness experts, it covers psychological and physical changes associated with age (both normal and pathological), including an important but rarely explored aspect of dementia known as wandering behavior. It also addresses the role of emerging technology. The 13 chapters are categorized into four parts. The first part presents an overview of aging and mobility issues, including discussions of how society is aging, traffic crash risks, age-related declines in functional abilities, and the driving skills needed for safe driving. A framework is presented for the issues related to aging and safe mobility. The second part discusses the current knowledge on the effects of medical conditions and medications on driving and crash risk. The third part discusses the issues and practices of driver screening and assessment and concludes with a discussion of driver licensing policy. The final part covers topics related to maintaining safe mobility in older adulthood including education and rehabilitation, vehicles and advanced technology, roadway design, driving retirement, and other community mobility options.

Driving behaviors in early stage dementia: a study using in-vehicle technology

According to the Alzheimers Association (2011), (1) in 8 people age 65 and older, and about one-half of people age 85 and older, have Alzheimers disease in the United States (US). There is evidence that drivers with Alzheimers disease and related dementias are at an increased risk for unsafe driving. Recent advances in sensor, computer, and telecommunication technologies provide a method for automatically collecting detailed, objective information about the driving performance of drivers, including those with early stage dementia. The objective of this project was to use in-vehicle technology to describe a set of driving behaviors that may be common in individuals with early stage dementia (i.e., a diagnosis of memory loss) and compare these behaviors to a group of drivers without cognitive impairment. Seventeen drivers with a diagnosis of early stage dementia, who had completed a comprehensive driving assessment and were cleared to drive, participated in the study. Participants had their vehicles instrumented with a suite of sensors and a data acquisition system, and drove 1-2 months as they would under normal circumstances. Data from the in-vehicle instrumentation were reduced and analyzed, using a set of algorithms/heuristics developed by the research team. Data from the early stage dementia group were compared to similar data from an existing dataset of 26 older drivers without dementia. The early stage dementia group was found to have significantly restricted driving space relative to the comparison group. At the same time, the early stage dementia group (which had been previously cleared by an occupational therapist as safe to drive) drove as safely as the comparison group. Few safety-related behavioral errors were found for either group. Wayfinding problems were rare among both groups, but the early stage dementia group was significantly more likely to get lost.

DRIVER HAND-HELD MOBILE PHONE USE AND SAFETY BELT USE

The purposes of the study were to identify hand-held mobile phone use trends for Michigan and to compare safety belt use between users and nonusers. Mobile phone and safety belt use was investigated by a direct observation survey of drivers at intersections in Michigan. Data were weighted to calculate mobile phone use and safety belt use rates statewide. The study showed 2.7% of Michigan drivers were using a mobile phone at any given daylight time. Safety belt use of current mobile phone users was significantly lower than those not using mobile phones.

Trends in driver and front-right passenger safety belt use in Michigan: 1984-1998.

As part of Michigans effort to track trends in safety belt use within the state over time, the University of Michigan Transportation Research Institute conducted 20 statewide surveys of safety belt use between 1984 and 1998. Results indicate that Michigan safety belt use trends for drivers and front-right passengers are similar to other statewide and national trends. Belt use in Michigan increased dramatically immediately after the state implemented its mandatory belt use law (secondary enforcement) followed by a smaller decline that leveled off at a rate more than 20 percentage points higher than before the law. Belt use was consistently higher among drivers than front-right passengers, older than younger front-outboard occupants, females than males, and front-outboard occupants exiting freeways than those stopped at local intersections. Examination of belt use trends in Michigan provides useful information for continued efforts to increase belt use in our state and for all states interested in meeting national goals for safety belt use for the year 2000 and beyond.

Factors affecting self-regulatory driving practices among older adults

Objective: The primary objective of this study was to better understand how self-regulatory driving practices at multiple levels of driver decision making are influenced by various factors. Specifically, the study investigated patterns of tactical and strategic self-regulation among a sample of 246 Australian older drivers. Of special interest was the relative influence of several variables on the adoption of self-regulation, including self-perceptions of health, functioning, and abilities for safe driving and driving confidence and comfort. Methods: The research was carried out at the Monash University Accident Research Centre, as part of its Ozcandrive study, a partnership with the Canadian Driving Research Initiative for Vehicular Safety in the Elderly (Candrive), and in conjunction with the University of Michigan Transportation Research Institute (UMTRI). Candrive/Ozcandrive represents the first study to follow a large group of older drivers over several years and collect comprehensive self-reported and objectively derived data on health, functioning, and driving. This study used a subset of data from the Candrive/Ozcandrive study. Upon enrolling in the study, participants underwent a comprehensive clinical assessment during which data on visual, cognitive, and psychomotor functioning were collected. Approximately 4 months after study enrollment, participants completed the Advanced Driving Decisions and Patterns of Travel (ADDAPT) questionnaire, a computer-based self-regulation instrument developed and pilot-tested at UMTRI. Results: Self-regulation among older adults was found to be a multidimensional concept. Rates of self-regulation were tied closely to specific driving situations, as well as level of decision making. In addition, self-regulatory practices at the strategic and tactical levels of decision making were influenced by different sets of factors. Conclusions: Continuing efforts to better understand the self-regulatory practices of older drivers at multiple levels of driver performance and decision making should provide important insights into how the transition from driving to nondriving can be better managed to balance the interdependent needs of public safety and personal mobility.

Driving avoidance by older adults: Is it always self-regulation?

Self-regulation shows promise as a means by which older adults can continue to drive at some level without having to stop altogether. Self-regulation is generally described as the process of modifying or adjusting ones driving patterns by driving less or intentionally avoiding driving situations considered to be challenging, typically in response to an awareness that driving skills have declined. However, most studies asking older adults whether they avoid certain driving situations or have reduced the amount of driving they do under certain circumstances have not delved deeper into the motivations for such avoidance or driving reduction. There are many reasons for modifying driving that have nothing to do with self-regulation, such as no longer needing to take trips at certain times of day because of changes in preferences or lifestyles. The purpose of this study was to examine self-regulatory practices among older adults at multiple levels of driver performance and decision making, taking into account the specific motivations for avoiding particular driving situations or engaging in other driving practices. Study participants completed a computer-based questionnaire on driving self-regulation. Results suggest that self-regulation is a complex process that cannot be defined simply by the reported driving modifications made by drivers. Understanding the motivations for these behaviors is necessary and the study showed that they are varied and differ considerably across driving situations. Reasons for driving avoidance or other practices were often more closely related to lifestyle or preferences than to self-regulation. Based on these findings, three distinct groups were identified with regard to whether and for what reasons participants modified their driving.

Importance of scenic byways in route choice: a survey of driving tourists in the United States

In order to develop more effective tourist information systems for use along scenic byways, it is important to know the characteristics of those people who include the presence of scenic byways in their selections of routes. Gaining a better understanding of these characteristics was the purpose of this study. The data presented here are from a United States (US) survey of the driving tourists information needs and preferences weighted to be representative of US tourist travelers. The study showed that when planning a route to a destination on an overnight automobile trip, the driving tourist is most concerned with factors related to the actual driving of the route, such as the directness, safety, amount of congestion, and distance. Of secondary importance are factors that make the route entertaining or pleasant to drive, including whether the route is a scenic byway. Analysis of the importance of scenic byways by several demographic factors showed little difference in importance ratings except for age and household income. Examination of importance ratings by trip characteristics showed that the presence of scenic byways in selecting a route was more important for the traveler whose trip purpose is a vacation, who is in the midst of a long distance and duration trip, who will be either camping or staying in a hotel, and who has planned the trip well in advance. These results suggest that scenic byways are an excellent area for the implementation and testing of in-vehicle information systems for the driving tourist.