Review of Studies on Older Drivers’ Behavior and Stress—Methods, Results, and Outlook

This paper presents a review on relevant studies and reports related to older drivers’ behavior and stress. Questionnaires, simulators, and on-road/in-vehicle systems are used to collect driving data in most studies. In addition, research either directly compares older drivers and the other drivers or considers participants according to various age groups. Nevertheless, the definition of ‘older driver’ varies not only across studies but also across different government reports. Although questionnaire surveys are widely used to affordably obtain massive data in a short time, they lack objectivity. In contrast, biomedical information can increase the reliability of a driving stress assessment when collected in environments such as driving simulators and on-road experiments. Various studies determined that driving behavior and stress remain stable regardless of age, whereas others reported degradation of driving abilities and increased driving stress among older drivers. Instead of age, many researchers recommended considering other influencing factors, such as gender, living area, and driving experience. To mitigate bias in findings, this literature review suggests a hybrid method by applying surveys and collecting on-road/in-vehicle data.

Predicting the Coping Skills of Older Drivers in the Face of Unexpected Situation

In recent years, when an older driver who cannot immediately recognize, judge, and operate properly faces an unexpected situation, they often panic, which may cause a traffic accident. However, there has not yet been enough discussion about the coping skills of older drivers in the face of this unexpected situation. Therefore, this study discusses the coping skills of older drivers in the face of unexpected situations. Moreover, we propose a coping skills prediction system (CP system). The CP system predicts coping skills from the tilt angle and angular velocity of the left foot when an older driver is driving or preparing to start a car. The experiment carried out two phases, a phase of driving a car and a phase of preparing to start the car. In the driving phase, the young and older driver drive the car in a driving simulator. The average age of the young driver group was ± standard deviation = 20.6 ± 0.7 years, and the age of the older driver group was 78.5 ± 5.1 years. The driving route included 15 cases in which collision accidents are likely to occur. We analyzed the experimental results of the driving phase and clarified the predictors of coping skills. Moreover, we analyzed the correlation between the left foot movement in driving and the left foot movement during preparing to start the car. As a result of the experiment, there was a 0.84 correlation between the tilt angle of the left foot of the older driver in driving and the tilt angle of the left foot of the older driver in preparing to start the car. The result shows that the coping skills can be predicted from the tilt angle of the left foot of the older driver during preparing to start the car. We showed that the coping skill can be predicted with an accuracy of 92% or 94% on average from the tilt angle and the angular velocity of the left foot while driving or preparing to start the car. Moreover, we clarified that the tilt angle of the left foot of a driver without coping skills is perpendicular to the ground compared to a driver with coping skills. This study is expected to contribute to the prevention of traffic accidents that occur in the face of an unexpected situation.

The Associations Between Older Driver Licensure Laws with Travel and Passenger Behaviors Among Adults Aged 65 Years or Older (United States, 2003–2017)

Introduction: The aging population has been rapidly growing in the United States (U.S.). In line with this trend, older adults’ mobility and transportation safety are an increasing priority. Many states have implemented driver licensure laws specific to older adults to limit driving among the elderly with driving skill decline. Evaluations of these laws have primarily focused on their safety benefits related to older drivers’ fatal crash rate or injury rate. However, very few studies investigated licensure law effects on older adults’ mobility. Objective: The objective of our study is to evaluate the association between older driver licensure laws and older adult daily traveling and passenger exposure. Methods: The 2003–2017 American Time Use Survey (ATUS) data were linked with statewide driver licensure law provisions. Adults aged 55–64 years were used as the reference group to control for the effects of non-licensure-law factors (e.g., economic trend). We used modified Poisson regressions with robust variance to estimate the relationships between licensure law provisions and the likelihoods of older men and women’s daily traveling and passenger behaviors. Results: Laws requiring a vision test at in-person renewal were associated with increased daily traveling likelihood for women aged 75 years or older, primarily as a passenger. Laws requiring a knowledge test were related to a reduced daily overall traveling likelihood for women aged 75 years or older. Conclusions: In general, licensure law provisions are not strongly related to older adults’ mobility, in particular for older male adults. Older female adults’ daily mobility may be more likely to be influenced by the change of licensure laws than older male adults. The existence of gender-based disparities in responding to licensure laws requires future studies to account for the gender difference in estimating the effects of those traffic policies on older adults’ mobility and traffic safety.

Improving the Driving of Community-Dwelling Older Canadians: A Randomized Controlled Trial

Older Canadians, similar to aging drivers in many other countries, want to drive, need to drive, and live in communities where driving is both valued and necessary for out-of-home participation. Many community-dwelling seniors are medically fit-to-drive, yet their collision risk remains higher than most other age groups, which some have attributed to their propensity to drive shorter distances in high-traffic areas (Antin et al., 2017). In this randomized controlled trial, the effect of a customized video-based older driver training program on behind-the-wheel performance was captured using the latest technology for an on-road evaluation. Results indicated the mean reduction in number of driving errors [mean (95% CI)=-12.0(-16.5, -7.6),p<0.001] favoured the intervention group where their change between baseline and 4-week follow-up was statistically significant [mean(95% CI)=-10.3(-13.8, -6.8),p<0.001], but not for the control group [mean (95% CI)=1.7(-0.08, 4.2), p>0.05]. Our novel, video-based approach that provided individualized feedback improved driving performance for older drivers. Part of a symposium sponsored by Transportation and Aging Interest Group.

Analysis of the impacts of risk factors on teenage and older driver injury severity using random-parameter ordered probit

The study analyzed injury severity of teenage and older drivers using 2015–2016 crash data from New Mexico. The fitness of the random-parameter ordered probit models developed for each age group was tested using likelihood ratio, comparing them to a unified model that combines both age groups, as well as comparing the random-parameter to fixed-parameter ordered probit for each age group. In both cases separate random-parameter ordered probit provided better results. It was found that vehicle type and age, lighting condition, alcohol or drug use, speeding, and seatbelt use were significant both for the teenage and older driver injury severity. The weather condition and gender were significant only in the teenage driver model, while driver inattention was significant for older drivers. The impacts of crash factors on injury severity was analyzed using marginal effects. The results indicate notable differences in the effects of contributing factors on driver injury severity between teenage and older drivers, including the sensitivity to changes in the mutual predictor parameter values.

Older Driver Crash Involvement and Fatalities, by Age and Sex, 2000–2017

Federal reporting of crash fatalities has limited age-by-sex stratification, but both age and sex are associated with driving reduction and cessation. We described older driver fatal crash involvement and fatalities using Fatality Analysis Reporting System data to calculate rates (per 100,000 licensed drivers, per 100,000 population) with age-by-sex stratifications. Nationally from 2000 through 2017, 110,422 drivers 65+ were involved in crashes resulting in at least one death within 30 days, and 67,843 of these older drivers died. Involvement and fatality rates per 100,000 licensed drivers in 2017 were lowest for females 65–69 (7.7 and 3.6, respectively) and highest for males age 85+ (34.3 and 25.5, respectively). Females had lower driver fatal crash involvement and fatality rates throughout the lifespan, even when rates generally decreased over time. Elaborating fatal crash trends and rates by age and sex helps to differentiate the public health burden of older driver crashes and fatalities.

Measuring the Applicability of Intersection-Based Older Driver Training Programs

Older drivers remain overrepresented in intersection crashes. Previous evidence suggests that the primary reason for this lies with their lack of scanning for potential threat vehicles while entering stop-controlled intersections. More so, secondary glances prove critical when the conditions obscure potential threat vehicles while approaching the intersection. Currently, simulator-based older driver training programs have proven effective in increasing the frequency of secondary glances taken by older drivers up to 2 years following the training. However, both the need for a full-scale driving simulator and participant dropout rates because of simulator sickness within training programs continue to limit the applicability of these alternatives. This study used a series of micro-scenarios to train older drivers in secondary glances, thus reducing the potential for participant dropouts resulting from simulator sickness. In addition, driver immersion levels varied across multiple training platforms, ranging from low to medium. A total of 91 participants between 67 and 86 years old were assigned to one of five groups. Three groups were provided active, secondary glance training on a driving simulator (one on a low immersion simulator and two on medium immersion simulators), a fourth group was provided passive training using a PowerPoint presentation, and the last group was a control with no training. Following training, all participants were evaluated in their personal vehicles while wearing head-mounted cameras. The medium immersion group resulted in the highest percentage of secondary glances (82%), whereas the control group resulted in the lowest percentage (42%). The results provide evidence to suggest that the training programs using micro-scenarios in medium and low immersion simulators can increase the frequency of secondary glances without having high dropout rates caused by simulator sickness.