Validation of an electronic device for measuring driving exposure

Subjective evaluations of self and others' driving behaviors: A comparative study involving data from drivers in Japan, China, and Vietnam

INTRODUCTION

This study explored the influence of personal attributes on subjectively-reported aggressive driving behaviors, with an emphasis on the inter-influences between subjectively-reported aggressive driving behaviors between self and other individuals. To determine this, a survey was conducted comprising participants' socio-demographic data, information on their history with automotive accidents, and subjective scales to report on the driving behaviors between self and others. More specifically, a four-factor shortened version of the Manchester Driver Behavior Questionnaire was used to collect data on the aberrant driving behaviors of "self" and "others."

METHOD

Participants were recruited from three countries, namely, Japan (1,250 responses), China (1,250), and Vietnam (1,000). This study only considered the "aggressive violations' factor," which was referred to as self-aggressive driving behaviors (SADB) and others' aggressive driving behaviors (OADB). After collecting the data, univariate and bivariate multiple regression models were employed to better understand the response patterns from both scales.

RESULTS

This study found that accident experience had the strongest influence on the reporting of aggressive driving behaviors (followed by education level). However, variation in countries was also found between both the rate of engagement in aggressive driving behavior and its recognition. In this study, highly educated Japanese drivers tended to evaluate others as safe, whereas highly educated Chinese drivers tended to evaluate others as aggressive. This discrepancy can likely be attributed to cultural norms and values. Meanwhile, evaluations from Vietnamese drivers seemed to differ depending on whether they drove cars or bikes, with additional influences as a result of the driving frequency. Furthermore, this study found that it was most difficult to explain the driving behaviors on the "other" scale reported by Japanese drivers.

PRACTICAL APPLICATIONS

These findings can aid policymakers and planners to develop road safety measures that reflect the behaviors of drivers in their respective countries.

The influence of achievement goals on objective driving behavior

Investigating psychological characteristics through self-reported measures (e.g., anger, sensation seeking) and dynamic behaviors through objective measures (e.g., speed, 2D acceleration, GPS position etc.) may allow us to better understand the behavior of at-risk drivers. To assess drivers' motivation, the theoretical framework of achievement goals has been studied recently. These achievement goals can influence the decision-making and behaviors of individuals engaged in driving. The four achievement goals in driving are: seeking to improve or to drive as well as possible (mastery-approach), to outperform other drivers (performance-approach), to avoid driving badly (mastery-avoidance), and to avoid being the worst driver (performance-avoidance). Naturalistic Driving Studies (NDS) provide access to the objective measurements of data not accessible through self-reported measurements (i.e., speed, accelerations, GPS position). Three dynamic criteria have been developed to characterize the behavior of motorists objectively: driving events, time spent above acceleration thresholds (longitudinal and transversal), and the extent of dynamic demands. All these criteria have been measured in different road contexts (e.g., plain). The aim of this study was to examine the predictive role of the four achievement goals on these objective driving behaviors. 266 drivers (96 women, 117 men) took part in the study, and 4 242 482 km was recorded during 8 months. Simultaneously, they completed the Achievement Goals in Driving Questionnaire. The main results highlighted that mastery-approach goals negatively predicted hard braking and the extent of dynamic demands on plain and hilly roads. Mastery-approach goals seem to be the most protective goals in driving. Future research on the promotion of mastery-approach goals in driving may be able to modify the behavior of at-risk drivers.

Examining the contribution of psychological resilience on self-reported and naturalistic driving behavior of older adults

INTRODUCTION

This study examined the contribution of psychological resilience on self-reported driving comfort, abilities, and restrictions, and on naturalistic driving (ND) behavior of older adults at two time points, five years apart (N = 111; Male: 65.8%, Mean age = 86.1 years).

METHOD

Participants from the Ozcandrive older driver cohort study completed a demographic questionnaire, functional assessments, psychosocial driving questionnaires, and a resilience scale. Participants' vehicles were equipped with a recording device to monitor driving behavior throughout the study. Over 1.7 million kilometers of ND data were analyzed.

RESULTS

There was a significant increase in resilience over time, and both self-reported and ND measures revealed reduced driving across five years. Hierarchical regression analyses using age, sex, driving exposure, functional measures, and resilience showed that adding resilience into the models at the final step resulted in statistically significant increases in the amount of variance explained for driving comfort during the day and night, perceived driving abilities, number of trips, trip distance, and proportion of night trips.

CONCLUSIONS

This research leveraged the longitudinal nature of the Ozcandrive study to provide the first insights into the role of resilience and ND. The observed patterns of reduced driving, captured by both subjective and objective measures, are suggestive of increased levels of self-regulation. As resilience is associated with adaptive coping skills, older adults with higher resilience may be able to more effectively engage in appropriate coping behaviors with regard to driving behavior, safety, and mobility.

PRACTICAL APPLICATIONS

Effective methods of increasing resilience in the context of driving is worthy of future research as it will provide valuable information about how older drivers navigate the process of aging as it relates to driving and may assist stakeholders in developing suitable measures to support older driver safety.

Disparities in Activity and Traffic Fatalities by Race/Ethnicity

INTRODUCTION

Traffic fatalities remain a major public health challenge despite progress made during recent decades. This study develops exposure-based estimates of fatalities per mile traveled for pedestrians, cyclists, and light-duty vehicle occupants and describes disparities by race/ethnicity, including a subanalysis of fatality rates during darkness and in urban areas.

METHODS

Estimates of person-miles traveled by mode and race/ethnicity group were derived from the 2017 National Household Travel Survey using replicate weights. Three-year average (2016‒2018) traffic fatalities were measured by mode and race/ethnicity group with the U.S. Fatality Analysis Reporting System. Fatality rates per mile traveled and CIs were calculated for each subgroup as well as separately for trips occurring during darkness and in urban areas. Analysis was conducted in 2021‒2022.

RESULTS

Exposure to traffic fatality differs by race/ethnicity group and by mode, indicating that adjustment for differential exposure is needed when estimating disparities. The authors find that fatality rates per 100 million miles traveled are systematically higher for Black and Hispanic Americans for all modes and notably higher for vulnerable modes (e.g., Black Americans died at more than 4 times the rate for White Americans while cycling, 33.71 [95% CI: 21.84, 73.83] compared with 7.53 [95% CI: 6.64, 8.69], and more than 2 times the rate while walking, 40.92 [95% CI: 36.58, 46.44] compared with 18.77 [95% CI: 17.30, 20.51]). Previous estimates that do not adjust for differential exposure may underestimate disparities by race/ethnicity. Observed disparities remained when considering only urban areas and appear to be exacerbated during darkness.

CONCLUSIONS

Traffic fatalities are a substantial and preventable public health challenge in America. Black and Hispanic Americans have higher traffic fatality rates per mile traveled than White Americans across the transportation system, requiring urgent attention.

Overestimation of self-reported driving exposure: Results from the SHRP2 Naturalistic Driving Study

OBJECTIVES

The accuracy of self-reported driving exposure has questioned the validity of using self-reported mileage to inform research questions. Studies examining the accuracy of self-reported driving exposure compared to objective measures find low validity, with drivers overestimating and underestimating driving distance. The aims of the current study were to (1) examine the discrepancy between self-reported annual mileage and driving exposure the following year and (2) investigate whether these differences depended on age and annual mileage.

METHODS

Two estimates of drivers' self-reported annual mileage collected during vehicle installation (obtained via prestudy questionnaires) and approximated annual mileage driven (based upon Global Positioning System data) were acquired from 3,323 participants who participated in the Strategic Highway Research Program 2 (SHRP2) Naturalistic Driving Study.

RESULTS

A Wilcoxon signed rank test showed that there was a significant difference between self-reported and annual driving exposure during participation in SHRP 2, with the majority of self-reported responses overestimating annual mileage the following year, irrespective of whether an ordinal or ratio variable was examined. Over 15% of participants provided self-reported responses with over 100% deviation, which were exclusive to participants underestimating annual mileage. Further, deviations in reporting differed between participants who had low, medium, and high exposure, as well as between participants in different age groups.

CONCLUSIONS

These findings indicate that although self-reported annual mileage is heavily relied on for research, such estimates of driving distance may be an overestimate of current or future mileage and can influence the validity of prior research that has utilized estimates of driving exposure.

Naturalistic driving patterns of older adults before and after cataract surgery

OBJECTIVE

Cataract surgery can have many benefits for older adults, including enabling continued ability to drive. However, it is not known how objectively measured driving patterns change after cataract surgery. The purpose of this study was to examine how participants drove before and after cataract surgery.

DESIGN

Longitudinal study.

PARTICIPANTS

Individuals from the Winnipeg site of Candrive (a longitudinal study of older drivers in Canada).

METHODS

An in-vehicle device monitored all trips taken in 1-second intervals, allowing for the analysis of distances driven, number of trips, time of trips, speeding, excessive braking/accelerating, and types of roadways.

RESULTS

Over the 4 years of data collection, there were 16 cases of participants having cataract surgery, whereby there was also suitable driving data for analyses. Participants drove 28% further after surgery (p = 0.022). They also drove further from home and more on primary roads (p < 0.05) and had fewer episodes of hard braking per distance travelled (p < 0.001). No other variables significantly changed.

CONCLUSIONS

This study suggests that older drivers changed some of their driving patterns after cataract surgery. Future studies could explore the effects of increased driving exposure, in conjunction with potentially safer driving behaviors, on overall driving safety after cataract surgery.

Comparison of self-report and objective measures of driving behavior and road safety: A systematic review

INTRODUCTION

This research systematically reviewed the existing literature in regards to studies which have used both self-report and objective measures of driving behavior. The objective of the current review was to evaluate disparities or similarities between self-report and objective measures of driving behavior.

METHODS

Searches were undertaken in the following electronic databases, PsycINFO, PubMed, and Scopus, for peer-reviewed full-text articles that (1) focused on road safety, and (2) compared both subjective and objective measures of driving performance or driver safety. A total of 22,728 articles were identified, with 19 articles, comprising 20 studies, included as part of the review.

RESULTS

The research reported herein suggested that for some behaviors (e.g., driving in stressful situations) there were similarities between self-report and objective measures while for other behaviors (e.g., sleepiness and vigilance states) there were differences between these measurement techniques. In addition, findings from some studies suggested that in-vehicle devices may be a valid measurement tool to assess driving exposure in older drivers.

CONCLUSIONS

Further research is needed to examine the correspondence between self-report and objective measures of driving behavior. In particular, there is a need to increase the number of studies which compare "like with like" as it is difficult to draw comparisons when there are variations in measurement tools used.

PRACTICAL APPLICATIONS

Incorporating a range of objective and self-report measurements tools in research would help to ensure that the methods used offer the most reliable measures of assessing on-road behaviors.

Louis R, Zanier N, Ryan L, LeBlanc D, Smith J, Yung R, Nyquist L, DiGuiseppi C, Li G, Mielenz T, Strogatz D. The effects of demographics, functioning, and perceptions on the relationship between self-reported and objective measures of driving exposure and patterns among older adults

The exploratory study reported here was intended to examine: how strongly subjectively reported driving avoidance behaviors (commonly referred to as self-regulation) and exposure were related to their objectively measured counterparts and whether it depended on the specific behavior; the extent to which gender and age play a role in the association between subjectively reported driving avoidance behaviors and exposure and their objectively measured counterparts; and the extent to which demographics, health and functioning, driving-related perceptions, and cognition influence the association between subjective and objective driving avoidance behaviors overall. The study used data from the Longitudinal Research on Aging Drivers (LongROAD) study, a multisite, prospective cohort study designed to generate empirical data for understanding the role of medical, behavioral, environmental, and technological factors in driving safety during the process of aging. Objective driving measures were derived from GPS/datalogger data from 2131 LongROAD participants' vehicles. The corresponding subjective measures came from a comprehensive questionnaire administered to participants at baseline that asked them to report on their driving exposure, patterns, and other aspects of driving. Several other variables used in the analyses came from the comprehensive questionnaire and an inperson clinical assessment administered to participants at baseline. A series of simple linear and logistic models were fitted to examine the relationship between the subjective and objective driving measures of interest, and a multivariable analysis was conducted to examine the potential role of selected factors in the relationship between objective and subjective driving avoidance behaviors. Results of the models are presented and overall findings are discussed within the context of the existing research literature.

Using naturalistic driving data to better understand the driving exposure and patterns of older drivers

OBJECTIVE

The aging of the population in the United States and elsewhere has brought increasing attention to the issue of safe driving and mobility among older adults. The overall objective of this research was to use naturalistic data collection to better understand driving exposure and driving patterns, 2 important contributors to crash risk.

METHODS

Data came from a study conducted at the University of Michigan Transportation Research Institute as part of the Integrated Vehicle-Based Safety System (IVBSS) program. A total of 108 randomly sampled drivers took part, with the sample stratified by age and sex. The age groups examined were 20 to 30 (younger), 40 to 50 (middle-aged), and 60 to 70 years old (older). Sixteen late-model Honda Accords were used as research vehicles and were driven by participants as their personal vehicles over the study period. Roughly the first 2 weeks of vehicle use comprised the baseline driving period, during which the IVBSS technologies were turned off (i.e., no warnings were presented to the drivers) but all onboard data were collected. For this article, only data from the baseline period were analyzed to limit any confounding effects that the safety technology may have had on driving behavior.

RESULTS

Results indicated that when looking at age independent of sex, older drivers (age 60-70) took fewer trips, drove fewer minutes, were less likely to drive at night, and had fewer high decelerations and speeding events than the youngest age group (20-30). They were also less likely to drive during peak morning traffic and on high-speed roads than their middle-age counterparts (40-50). Across all age groups, there were few differences by sex, with the exception that females drove fewer miles and fewer minutes and had fewer high decelerations than males. When both age and sex were taken into account, it was often the group of females age 60-70 that appeared to account for many of the age and sex differences found in driving exposure and patterns.

CONCLUSIONS

Future research in this area would benefit from larger scale and longitudinal study designs so that changes in driving exposure and patterns over time among large samples of drivers could be examined.

First and second eye cataract surgery and driver self-regulation among older drivers with bilateral cataract: a prospective cohort study

Background

Driving a car is the most common form of transport among the older population. Common medical conditions such as cataract, increase with age and impact on the ability to drive. To compensate for visual decline, some cataract patients may self-regulate their driving while waiting for cataract surgery. However, little is known about the self-regulation practices of older drivers throughout the cataract surgery process. The aim of this study is to assess the impact of first and second eye cataract surgery on driver self-regulation practices, and to determine which objective measures of vision are associated with driver self-regulation.

Methods

Fifty-five older drivers with bilateral cataract aged 55+ years were assessed using the self-reported Driving Habits Questionnaire, the Mini-Mental State Examination and three objective visual measures in the month before cataract surgery, at least one to three months after first eye cataract surgery and at least one month after second eye cataract surgery. Participants’ natural driving behaviour in four driving situations was also examined for one week using an in-vehicle monitoring device. Two separate Generalised Estimating Equation logistic models were undertaken to assess the impact of first and second eye cataract surgery on driver-self-regulation status and which changes in visual measures were associated with driver self-regulation status.

Results

The odds of being a self-regulator in at least one driving situation significantly decreased by 70% after first eye cataract surgery (OR: 0.3, 95% CI: 0.1–0.7) and by 90% after second eye surgery (OR: 0.1, 95% CI: 0.1–0.4), compared to before first eye surgery. Improvement in contrast sensitivity after cataract surgery was significantly associated with decreased odds of self-regulation (OR: 0.02, 95% CI: 0.01–0.4).

Conclusions

The findings provide a strong rationale for providing timely first and second eye cataract surgery for older drivers with bilateral cataract, in order to improve their mobility and independence.

Do older drivers with bilateral cataract self-regulate their driving while waiting for first eye cataract surgery?

Objectives

To analyze the association between visual impairment and driver self-regulation among a cohort of older drivers waiting for first eye cataract surgery.

Methods

Ninety-six drivers with bilateral cataract aged 55+ years were assessed before first eye cataract surgery. Data collection consisted of a researcher-administered questionnaire, objective visual measures (visual acuity, contrast sensitivity and stereopsis), a visual attention test (the useful field of view test) and a cognitive test (the Mini-Mental State Examination). Driver self-regulation practices were collected using the Driving Habits Questionnaire and were also measured with an in-vehicle monitoring device. Characteristics of self-regulators and non-self-regulators were compared and a logistic regression model was used to examine the association between 3 objective visual measures and driver self-regulation status.

Results

After controlling for potential confounding factors, only binocular contrast sensitivity (p=0.01), age (p=0.03) and gender (p=0.03) were significantly associated with driver self-regulation status. The odds of participants with better contrast sensitivity scores (better vision) self-regulating their driving in at least 1 driving situation decreased (odds ratio [OR]: 0.01, 95% CI: 0.00-0.28) while those of increasing age reported an increased odds of self-regulating their driving (OR: 1.08, 95% CI: 1.01-1.15). The odds of males self-regulating their driving was decreased compared with females (OR: 0.28, 95% CI: 0.09-0.86).

Conclusions

Worse binocular contrast sensitivity scores, increasing age and being female were significantly associated with driver self-regulation. The study highlighted that while self-regulation was common among cataract patients, a proportion of those with poor vision did not self-regulate. Further research should determine how cataract patients could benefit from self-regulation strategies while waiting for cataract surgery.

A validation study comparing self-reported travel diaries and objective data obtained from in-vehicle monitoring devices in older drivers with bilateral cataract

BACKGROUND

Advances in technology have made it possible to examine real-world driving using naturalistic data obtained from in-vehicle monitoring devices. These devices overcome the weaknesses of self-report methods and can provide comprehensive insights into driving exposure, habits and practices of older drivers.

AIM

The aim of this study is to compare self-reported and objectively measured driving exposure, habits and practices using a travel diary and an in-vehicle driver monitoring device in older drivers with bilateral cataract.

METHODS

A cross-sectional study was undertaken. Forty seven participants aged 58-89 years old (mean=74.1; S.D.=7.73) were recruited from three eye clinics over a one year period. Data collection consisted of a cognitive test, a researcher-administered questionnaire, a travel diary and an in-vehicle monitoring device. Participants' driving exposure and patterns were recorded for one week using in-vehicle monitoring devices. They also completed a travel diary each time they drove a motor vehicle as the driver. Paired t-tests were used to examine differences/agreement between the two instruments under different driving circumstances.

RESULTS

The data from the older drivers' travel diaries significantly underestimated the number of overall trips (p<0.001), weekend trips (p=0.002) and trips during peak hour (p=0.004). The travel diaries also significantly overestimated overall driving duration (p<0.001) and weekend driving duration (p=0.003), compared to the data obtained from the in-vehicle monitoring devices. No significant differences were found between instruments for kilometres travelled under any of the driving circumstances.

CONCLUSIONS

The results of this study found that relying solely on self-reported travel diaries to assess driving outcomes may not be accurate, particularly for estimates of the number of trips made and duration of trips. The clear advantages of using in-vehicle monitoring devices over travel diaries to monitor driving habits and exposure among an older population are evident.

Associations Between Health and Driving in an Older Adult Cohort in Rancho Bernardo

OBJECTIVE

The purpose of this study was to identify the associations between health and health care utilization with driving patterns in a cohort of older adults.

METHOD

In 2012, a total of 1,826 surviving participants in the Rancho Bernardo cohort were sent a health and driving pattern survey; 1,277 were returned.

RESULTS

The majority of the respondents (1,151, 91%) were still driving. Older age, female sex, hospitalizations, emergency department (ED) visits and physical therapy visits, neurological disease, depression, limited vision, and limited hearing were associated with non-driving status. A total of 809 (71%) of drivers reported no citations or crashes in the last 5 years.

DISCUSSION

The vast majority of older drivers in this cohort continued to drive, and did so safely. Health care utilization, medications, medical conditions, and self-assessment of health were associated with non-driving status. Prospective studies are needed to clarify the temporal relationships between these factors.

Young drivers' responses to anti-speeding advertisements: Comparison of self-report and objective measures of persuasive processing and outcomes

OBJECTIVE

Self-report measures are typically used to assess the effectiveness of road safety advertisements. However, psychophysiological measures of persuasive processing (i.e., skin conductance response [SCR]) and objective driving measures of persuasive outcomes (i.e., in-vehicle Global Positioning System [GPS] devices) may provide further insights into the effectiveness of these advertisements. This study aimed to explore the persuasive processing and outcomes of 2 anti-speeding advertisements by incorporating both self-report and objective measures of speeding behavior. In addition, this study aimed to compare the findings derived from these different measurement approaches.

METHODS

Young drivers (N = 20, M age = 21.01 years) viewed either a positive or negative emotion-based anti-speeding television advertisement. While viewing the advertisement, SCR activity was measured to assess ad-evoked arousal responses. The RoadScout GPS device was then installed in participants' vehicles for 1 week to measure on-road speed-related driving behavior. Self-report measures assessed persuasive processing (emotional and arousal responses) and actual driving behavior.

RESULTS

There was general correspondence between the self-report measures of arousal and the SCR and between the self-report measure of actual driving behavior and the objective driving data (as assessed via the GPS devices).

CONCLUSIONS

This study provides insights into how psychophysiological and GPS devices could be used as objective measures in conjunction with self-report measures to further understand the persuasive processes and outcomes of emotion-based anti-speeding advertisements.

Seasonal and Weather Effects on Older Drivers' Trip Distances

The purpose of this study was to determine if season or weather affected the objectively measured trip distances of older drivers (≥ 70 years; n = 279) at seven Canadian sites. During winter, for all trips taken, trip distance was 7 per cent shorter when controlling for site and whether the trip occurred during the day. In addition, for trips taken within city limits, trip distance was 1 per cent shorter during winter and 5 per cent longer during rain when compared to no precipitation when controlling for weather (or season respectively), time of day, and site. At night, trip distance was about 30 per cent longer when controlling for season and site (and weather), contrary to expectations. Together, these results suggest that older Canadian drivers alter their trip distances based on season, weather conditions, and time of day, although not always in the expected direction.

Older driver estimates of driving exposure compared to in-vehicle data in the Candrive II study

OBJECTIVE

Most studies on older adults' driving practices have relied on self-reported information. With technological advances it is now possible to objectively measure the everyday driving of older adults in their own vehicles over time. The purpose of this study was to examine the ability of older drivers to accurately estimate their kilometers driven over one year relative to objectively measured driving exposure.

METHODS

A subsample (n = 159 of 928; 50.9% male) of Candrive II participants (age ≥ 70 years of age) was used in these analyses based on strict criteria for data collected from questionnaires as well as an OttoView-CD Autonomous Data Logging Device installed in their vehicle, over the first year of the prospective cohort study.

RESULTS

Although there was no significant difference overall between the self-reported and objectively measured distance categories, only moderate agreement was found (weighted kappa = 0.57; 95% confidence interval, 0.47-0.67). Almost half (45.3%) chose the wrong distance category, and some people misestimated their distance driven by up to 20,000 km. Those who misjudged in the low mileage group (≤5000 km) consistently underestimated, whereas the reverse was found for those in the high distance categories (≥ 20,000); that is, they always overestimated their driving distance.

CONCLUSIONS

Although self-reported driving distance categories may be adequate for studies entailing broad group comparisons, caution should be used in interpreting results. Use of self-reported estimates for individual assessments should be discouraged.

CAN INTERMITTENT VIDEO SAMPLING CAPTURE INDIVIDUAL DIFFERENCES IN NATURALISTIC DRIVING?

We examined the utility and validity of intermittent video samples from black box devices for capturing individual difference variability in real-world driving performance in an ongoing study of obstructive sleep apnea (OSA) and community controls. Three types of video clips were coded for several dimensions of interest to driving research including safety, exposure, and driver state. The preliminary findings indicated that clip types successfully captured variability along targeted dimensions such as highway vs. city driving, driver state such as distraction and sleepiness, and safety. Sleepiness metrics were meaningfully associated with adherence to PAP (positive airway pressure) therapy. OSA patients who were PAP adherent showed less sleepiness and less non-driving related gaze movements than nonadherent patients. Simple differences in sleepiness did not readily translate to improvements in driver safety, consistent with epidemiologic evidence to date.

The use of self-report exposure measures among novice motorcyclists: appropriateness and best practice recommendations

OBJECTIVES

While self-report methods to collect exposure information have large practical advantages in many research contexts, little research has specifically investigated the reliability and validity of motorcyclists' self-reported exposure. The present study aimed to examine the reliability and validity of different self-report exposure measures and to provide recommendations on best practice self-report riding exposure questions.

METHODS

The reliability and validity of different self-report exposure measures were examined amongst novice motorcyclists through t-tests, Bland Altman plots, coefficients of variation, and correlations.

RESULTS

The most valid and reliable data was provided when riding exposure was asked for the current average week rather than earlier and longer periods, and in units of time rather than distance or number of trips. The greater reliability of riding exposure found amongst commuting and rural riders compared to recreational and metropolitan riders respectively and at the second interview compared to the first suggests that factors such as riding purposes, geographical locations, and riding experience can contribute to measurement error.

CONCLUSIONS

If self-reported odometer readings are used, questions on whether the respondents share their own bike or ride more than one bike, and a built-in process to ensure respondents report the exact odometer reading on their bike are recommended. It is recommended that self-report riding exposure questions ask about the hours of riding for the current average week, and data on riding purposes, locations, and experience are also collected.

The Canadian Safe Driving Study-Phase I pilot: Examining potential logistical barriers to the full cohort study

Multiple organizations and task forces have called for a reliable and valid method to identify older drivers who are medically unfit to drive. The development of a clinical decision rule for this type of screening requires data from a longitudinal prospective cohort of older drivers. The aim of this article is to identify potential design, sampling and data collection barriers to such studies based on an analysis of the Canadian Safe Driving Study-phase I pilot (Candrive I). A convenience sample of 100 active older drivers aged 70 years or more was recruited through the aid of a seniors' organization, 94 of whom completed the full study (retention rate 94%). Data were collected over the course of 1 year on various driving behaviours, as well as on cognitive, physical and mental functioning. Driving patterns were recorded using driving diaries, logs and electronic devices. Driving records from the Ministry of Transportation of Ontario (MTO) were obtained for the 3-year period preceding the study initiation and up to 1 year following study completion. An increased burden of illness was observed as the number of medical diagnoses and medication use increased over the study period. Study participants were involved in a total of five motor vehicle collisions identified through MTO records, which was comparable to the Ontario annual collision rate of 4.1% for drivers aged 75 years or older. In sum, many of the relevant logistical and practical barriers to studying a large sample of older drivers longitudinally have been shown to be addressable, supporting the feasibility of completing a large prospective cohort study of older drivers.

Development and evaluation of a driving observation schedule (DOS) to study everyday driving performance of older drivers

This paper describes the development and evaluation of an on-road procedure, the Driving Observation Schedule (DOS), for monitoring individual driving behavior. DOS was developed for use in the Candrive/Ozcandrive five-year prospective study of older drivers. Key features included observations in drivers' own vehicles, in familiar environments chosen by the driver, with start/end points at their own homes. Participants were 33 drivers aged 75+ years, who drove their selected route with observations recorded during intersection negotiation, lane-changing, merging, low speed maneuvers and maneuver-free driving. Driving behaviors were scored by a specialist occupational therapy driving assessor and another trained observer. Drivers also completed a post-drive survey about the acceptability of DOS. Vehicle position, speed, distance and specific roadways traveled were recorded by an in-vehicle device installed in the participant's vehicle; this device was also used to monitor participants' driving over several months, allowing comparison of DOS trips with their everyday driving. Inter-rater reliability and DOS feasibility, acceptability and ecological validity are reported here. On average, drivers completed the DOS trip in 30.48min (SD=7.99). Inter-rater reliability measures indicated strong agreement between the trained and the expert observers: intra-class correlations (ICC)=0.905, CI 95% 0.747-0.965, p<0.0001; Pearson product correlation, r (18)=.83, p<0.05. Standard error of the measurement (SEM), method error (ME) and coefficient of variation (CV) measures were consistently small (3.0, 2.9 & 3.3%, respectively). Most participants reported being 'completely at ease' (82%) with the driving task and 'highly familiar with the route' (97%). Vehicle data showed that DOS trips were similar to participants' everyday driving trips in roads used, roadway speed limits, drivers' average speed and speed limit compliance. In summary, preliminary findings suggest that DOS can be scored reliably, is of feasible duration, is acceptable to drivers and representative of everyday driving. Pending further research with a larger sample and other observers, DOS holds promise as a means of quantifying and monitoring changes in older drivers' performance in environments typical of their everyday driving.

Determining the validity of the AMA guide: A historical cohort analysis of the assessment of driving related skills and crash rate among older drivers

BACKGROUND

Chronic health conditions associated with ageing can lead to changes in driving ability. The Canadian Driving Research Initiative for Vehicular Safety in the Elderly (Candrive II) is a 5-year prospective study funded by the Canadian Institutes of Health Research aiming to develop an in-office screening tool that will help clinicians identify potentially at-risk older drivers. Currently, no tools exist to directly predict the risk of motor vehicle collision (MVC) in this population. The American Medical Association (AMA), in collaboration with the National Highway Traffic Safety Association, has designed an opinion-based guide for assessing medical fitness to drive in older adults and recommends that physicians use the Assessment of Driving Related Skills (ADReS) as a test battery to measure vision, cognition and motor/somatosensory functions related to driving. The ADReS consists of the Snellen visual acuity test, visual fields by confrontation test, Trail Making Test part B, clock drawing test, Rapid Pace Walk, and manual tests of range of motion and motor strength. We used baseline data from the Candrive/Ozcandrive common cohort of older drivers to evaluate the validity of the ADReS subtests. We hypothesized that participants who crashed in the 2 years before the baseline assessment would have poorer scores on the ADReS subtests than participants who had not crashed.

METHODS

In the Candrive/Ozcandrive study, 1230 participants aged 70 years or older were recruited from 7 Canadian cities, 1 Australian city and 1 New Zealand city, all of whom completed a comprehensive clinical assessment at study entry. The assessment included all tests selected as part of the ADReS. For this historical cohort study, data on all crashes (at-fault and non-at-fault) that occurred within 2 years preceding the baseline assessment were obtained from the respective licensing jurisdictions. Those who crashed were compared to those who had not crashed on their ADReS subtest scores using Pearson's chi-squared test and Student's t-test.

RESULTS

Sixty-three of the 1230 participants (5.1%) were involved in an MVC within the 2 years preceding the baseline assessment. Contrary to our hypothesis, there were no statistically significant associations between abnormal performance on the tests constituting the ADReS and history of crash in the previous 2 years (p>0.01).

DISCUSSION

We found that a history of crash in the previous 2 years was not associated with abnormalities on the subtests comprising the ADReS. This suggests the need for prospective analyses of risk factors over time to establish sensitive, valid predictors of crash that can be incorporated in clinical practice guidelines.

The relationship between cognitive performance, perceptions of driving comfort and abilities, and self-reported driving restrictions among healthy older drivers

The objective of the present study was to examine the relationship between cognitive performance, driver perceptions and self-reported driving restrictions. A cross-sectional analysis was conducted on baseline data from Candrive II, a five-year prospective cohort study of 928 older drivers aged 70-94 years from seven cities. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) as well as the Trail Making Test, parts A and B. Driver perceptions were assessed using the Day and Night Driving Comfort Scales and the Perceived Driving Abilities scale, while driving practices were captured by the Situational Driving Frequency and Avoidance scales, as well as the Driving Habits and Intentions Questionnaire. The baseline data indicates this cohort is largely a cognitively intact group. Univariate regression analysis showed that longer Trails A and B completion times were significantly, but only modestly associated with reduced driving frequency and perceived driving abilities and comfort, as well as a significant tendency to avoid more difficult driving situations (all p<.05). Most of these associations persisted after adjusting for age and sex, as well as indicators of health, vision, mood and physical functioning. Exceptions were Trails A and B completion times and situational driving frequency, as well as time to complete Trails B and current driving restrictions. After adjusting for the confounding factors, the total MoCA score was not associated with any of the driving measure scores while the number of errors on Trails A was significantly associated only with situational driving frequency and number of errors on Trails B was significantly associated only with situational driving avoidance. Prospective follow-up will permit examination of whether baseline cognition or changes in cognition are associated with changes in driver perceptions, actual driving restrictions and on-road driving outcomes (e.g., crashes, violations) over time.

Findings from the Candrive/Ozcandrive study: Low mileage older drivers, crash risk and reduced fitness to drive

Previous research has found that only older drivers with low annual driving mileages had a heightened crash risk relative to other age groups. These drivers tend to drive mainly in urban areas, where the prevalence of complex traffic situations increases crash risk. However it might also be that some drivers may have reduced their driving due to perceived or actual declines in driving fitness. This paper uses Canadian and Australian data from the Candrive/Ozcandrive older driver study to investigate the association between annual driving distances and a set of driving-related factors, including fitness to drive. All drivers in the Candrive/Ozcandrive older driver cohort study were allocated to one of three groups according to their self-reported annual driving distances: <5001km; >5000 and <15,000km; and 15,000km or greater. Relationships between these driving-distance categories and: (a) self-reported crash data; (b) various Year 1 'fitness to drive' performance measures; and (c) self-perceptions of driving ability and of comfort while driving, were determined. Results confirmed the previously reported association between low mileage and heightened crash risk. Further, low mileage drivers performed relatively poorly on a wide range of performance measures, perceived their own driving ability as lower, and reported lower comfort levels when driving in challenging situations, compared to the higher mileage drivers. In most instances, these differences were statistically significant. The paper provides further evidence that the so-called 'older driver problem' is most pertinent to low mileage drivers, and that this is due in part to low mileage drivers tending to have reduced fitness to drive. This higher risk group represented a fairly small proportion of the sample in this study.

Effect of cognitive status on self-regulatory driving behavior in older adults: an assessment of naturalistic driving using in-car video recordings

Previous findings that older drivers engage in strategic self-regulatory behaviors to minimize perceived safety risks are primarily based on survey reports rather than actual behavior. This study analyzed in-car video recording of naturalistic driving of 18 patients with Alzheimer disease (AD) and 20 age-matched controls in order to (1) characterize self-regulatory behaviors engaged by older drivers and (2) assess how behaviors change with cognitive impairment. Only participants who were rated "safe" on a prior standardized road test were selected for this study. Both groups drove primarily in environments that minimized the demands on driving skill and that incurred the least risk for involvement in major crashes. Patients with AD displayed further restrictions of driving behavior beyond those of healthy elderly individuals, suggesting additional regulation on the basis of cognitive status. These data provide critical empirical support for findings from previous survey studies indicating an overall reduction in driving mobility among older drivers with cognitive impairment.

Examination of naturalistic driving practices in drivers with Parkinson's disease compared to age and gender-matched controls

A few studies suggest that drivers with Parkinson's disease (PD) may self-regulate or modify their driving behavior more than drivers without neurological disorders; however findings are limited to self-report. The purpose of this study was to objectively examine whether drivers with PD show more restrictive driving practices (exposure and patterns). Electronic devices were installed in the vehicles of 27 drivers with PD (71.6±6.6; 78% men) and 20 matched controls (70.6±7.9; 80% men) for two weeks and driving data were matched with aerial maps, weather and daylight archives and trip logs to examine driving context. Compared to controls, the PD group drove significantly less overall (number of trips, kilometres, duration), and proportionately less at night and on days with bad weather suggesting more restricted driving practices, congruent with lower ratings of driving comfort and abilities. However, they may not necessarily drive more cautiously or safely as they drove significantly faster (and over the speed limit) on highways and freeways and 19% reported driving problems over the two weeks. These preliminary findings need to be replicated and longitudinal studies using objective indicators are needed to examine changes in driving practices, as well as crash outcomes, as disease severity progresses.

Self-regulatory practices of drivers with Parkinson's disease: accuracy of patient reports

BACKGROUND

Studies suggest that drivers with Parkinson's disease (PD) are more likely than controls to restrict their exposure and avoid challenging situations possibly to compensate for declining abilities; however it is questionable whether patient reports should be taken at face value. To address this issue, this study examined agreement between self-reported and actual driving practices in drivers with and without PD.

METHODS

Two electronic devices (one with GPS) were installed in the vehicles of 26 drivers with PD (mean age 71.5 ± 6.8, 77% men) and 20 controls (mean age 70.6 ± 7.9, 80% men) for two weeks. Participants completed a questionnaire on usual driving patterns, scales on Situational Driving Frequency (SDF) and Avoidance (SDA), the MoCA and an interview.

RESULTS

Self-estimates of distance driven (km) over the two weeks were inaccurate in both groups; however the tendency to under-estimate was more pronounced in PD drivers. Drivers with PD reported more self-restrictions (higher SDA scores, p < .01; lower SDF scores, p < .05), yet drove more at night, in bad weather, in rush hour and on highways than they reported. Drivers with PD had significantly lower MoCA scores overall (p < .01) and on the memory subtest (p < .05), however, MoCA scores were not correlated with self-reported restrictions, or actual driving distance in either group.

CONCLUSIONS

These findings indicate that patient reports of driving behavior should not be taken at face value by researchers or clinicians. Patients with PD may be more likely than drivers in general to have problems with recall and possibly less awareness of their driving practices.

Naturalistic Study of Winter Driving Practices by Older Men and Women: Examination of Weather, Road Conditions, Trip Purposes, and Comfort

La plupart des études sur les pratiques de conduite des aînés sont basées sur des données d’autoévaluation ; aucune n’a examiné objectivement leurs habitudes de conduite hivernale. Nous avons utilisé des appareils électroniques associés à des journaux de voyages, des cartes numériques et des archives météorologiques, afin d’examinerétudier les modes de conduite des personnes âgées de 65 à 91 sur deux semaines consécutives entre novembre 2008 et mars 2009. La conduite de nuit différait selon le mois, montrant l’importance des facteurs saisonniers, en particulier la quantité de lumière du jour. Bien que 69 pour cent de notre échantillon ait conduit les jours de mauvais temps, les aînés ont montré être significativement plus susceptibles de faire des voyages à des fins sociales ou de divertissement les jours de beau temps, et ils ont entrepris des voyages plus longs les jours offrant de bonnes conditions routières. Les scores de confort de conduite, notamment pour la conduite de nuit, étaient liés de manière significative aux indicateurs multiples de l’exposition et des habitudes, y compris au rayon autour du domicile. Comparativement aux hommes, les femmes ont obtenu des scores de conduite significativement plus bas, et ont été moins susceptibles de conduire quand les conditions metéorologiques et routières étaient défavorables.

Can we use digital life-log images to investigate active and sedentary travel behaviour? Results from a pilot study

BACKGROUND

Active travel such as walking and cycling has potential to increase physical activity levels in sedentary individuals. Motorised car travel is a sedentary behaviour that contributes to carbon emissions. There have been recent calls for technology that will improve our ability to measure these travel behaviours, and in particular evaluate modes and volumes of active versus sedentary travel. The purpose of this pilot study is to investigate the potential efficacy of a new electronic measurement device, a wearable digital camera called SenseCam, in travel research.

METHODS

Participants (n = 20) were required to wear the SenseCam device for one full day of travel. The device automatically records approximately 3,600 time-stamped, first-person point-of-view images per day, without any action required by the wearer. Participants also completed a self-report travel diary over the same period for comparison, and were interviewed afterwards to assess user burden and experience.

RESULTS

There were a total of 105 confirmed journeys in this pilot. The new SenseCam device recorded more journeys than the travel diary (99 vs. 94). Although the two measures demonstrated an acceptable correlation for journey duration (r = 0.92, p < 0.001) self-reported journey duration was over-reported (mean difference 154 s per journey; 95% CI = 89 to 218 s; 95% limits of agreement = 154 ± 598 s (-444 to 752 s)). The device also provided visual data that was used for directed interviews about sources of error.

CONCLUSIONS

Direct observation of travel behaviour from time-stamped images shows considerable potential in the field of travel research. Journey duration derived from direct observation of travel behaviour from time-stamped images appears to suggest over-reporting of self-reported journey duration.

Exposure to traffic and risk of hospitalization due to injuries

Research on the risk of motor vehicle injuries and their relationship with the amount of travel has been only partially analyzed. The few individual exposure assessments are related to very specific subsets of the driving and traveling populations. This study analyzes the relationship between kilometers traveled and hospitalization due to motor vehicle injuries. Twelve thousand three hundred and sixty nine Spanish university graduates from the Seguimiento Universidad de Navarra multipurpose cohort study were evaluated. They had not been hospitalized due to motor vehicle injuries at baseline and were followed up to eight years. Biannual questionnaires allowed for self-reporting of kilometers traveled in motor vehicles, together with incidence of hospitalization. Covariates in the Cox regression models included age and gender and baseline use of safety belt while driving, driving a vehicle with driver-side airbag, driving a motorcycle, and drinking and driving. There were 49,766 participant-years with an average yearly travel of 7,828 km per person-year. Thirty-six subjects reported a first hospitalization event during this time. The adjusted hazard ratio per additional kilometer traveled was 1.00005 (95% confidence interval 1.000013 to 1.000086). Even the smallest of reductions in the amount of kilometers traveled (from an average of 3,250 km per year to 1,000) has a statistically significant protective effect on the likelihood of sustaining hospitalization due to motor vehicle injury (aHR 0.9, 95% CI 0.78 to 0.98). In light of current policies aimed to reduce motorized traffic due to environmental concerns, it may be appropriate to consider the additional health benefit related to reductions in injuries.

Examination of driving comfort and self-regulatory practices in older adults using in-vehicle devices to assess natural driving patterns

Several studies have shown that age, gender, visual problems and confidence are associated with self-regulatory practices such as reduced exposure and avoidance of night and highway driving. To date, however, self-regulation has only been examined through self-report. The purpose of this study was to further our understanding of the association between driver characteristics, perceptions and self-regulation by monitoring the patterns of 61 drivers (mean age 80.4+/-5.5; 59% women) for one week using in-vehicle devices. Usual self-regulatory practices were assessed using the Situational Driving Frequency (SDF) and Avoidance (SDA) Scales, while perceptions were measured using the Driving Comfort and Perceived Driving Abilities Scales. Additional evidence for test-retest reliability was obtained with a separate sample of 39 older drivers. Lower comfort and poorer perceived abilities were significantly related to actual behavior: reduced exposure (km, duration) in general and at night, average and maximum radii from home and driving in challenging situations (such as on highways). Neither sex nor age was associated with any of the driving indicators. While longitudinal studies are required to determine temporality (when drivers change their behavior) and directionality (does lower comfort lead to driving restrictions or vice versa), this is the first study to demonstrate that driver perceptions are associated with actual self-regulatory practices.

Correspondence between self-reported and objective measures of driving exposure and patterns in older drivers

The driving behavior of older adults has been traditionally examined using questionnaires and diaries. The accuracy of self-reports has been questioned, and in-vehicle recording devices touted as more objective measures of real-world driving. The purposes of this study were to replicate and extend prior research comparing self-report and actual measures of driving exposure and patterns. Two electronic devices were installed in the vehicles of 61 drivers (67-92 years, 59% women) who were instructed to drive as usual over 1-week. Participants completed trip logs, daily diaries, a questionnaire on usual driving habits, ratings of situational driving frequency and avoidance and a follow-up interview. Only 53% of the sample attempted to estimate how far they had driven over the week and self-estimates were inaccurate (ME=77.5 km; CV=44.5%). Drivers tended to miss a significant number of trips and stops in their diaries. Driving behavior over the week was fairly consistent with usual practices regarding time of day, driving in certain areas, and night driving. However, subjects drove in challenging situations more than usual. Triangulating multiple sources of electronic and self-reported data provided a better understanding about the behavior of older drivers.

Is chest x-ray an adequate screening tool for the diagnosis of blunt thoracic aortic injury?

BACKGROUND

Blunt thoracic aortic injuries (BTAI) have a high mortality rate. For survivors, chest X-ray (CXR) findings are used to determine the need for further diagnostic testing with chest computerized tomography with angiography (CTA) or conventional angiography. We set to determine the adequacy of utilizing CXR alone as a screening tool for BTAI.

METHODS

All patients diagnosed with BTAI at a level I trauma-center during a 7-year-period were identified. CXRs of these patients and those of a control group of blunt trauma patients with an injury severity score >15 were reviewed by four trauma surgeons blinded to the diagnosis. Based on each CXR viewed, the surgeons decided if they would have proceeded to chest CTA, angiography, or required no further studies to rule out BTAI.

RESULTS

In the 7-year-period, 83 patients had BTAI. CXRs were available in 45 patients. The four surgeons viewed 96 CXRs including those of 51 controls. Based on the CXR appearance in patients with BTAI, the surgeons chose to proceed to chest CTA in 38 patients (84.4%), conventional aortography in two patients (4.4%), and no further testing in five patients (11.2%). A widened mediastinum (75%) and loss of the aorto-pulmonary window (40%) were the most frequent CXR abnormalities. Patients with BTAI were more likely to have an abnormal CXR-40 of 45 (88.8%) patients when compared with the controls-25 of 51 (49%)patients-p < 0.001.

CONCLUSIONS

Although CXR is a sensitive screening modality, it failed to identify the possibility of BTAI in 11% of patients. The liberal use of chest CTA after high speed motor vehicle crashes is recommended to minimize the incidence of missed BTAI.

In defence of the 'low-mileage bias'

There has been a long-recognised association between extent of driving and crash involvement: the lower the annual mileage driven, the higher the per-distance crash rate. Because older drivers generally drive less distance per year than others, this association has been used to explain much of their apparent over-involvement in crashes. Several studies from different countries around the world have demonstrated this 'low-mileage bias' and the relative safety of older drivers. However all studies have relied upon self-reported crash involvement and driving activity. Staplin et al. [Staplin, L., Gish, K., Joyce, J., 2008. 'Low mileage bias' and related policy implications-a cautionary note. Accident Analysis and Prevention 40, 1249-1252] have drawn attention to the discrepancy between self-reported and odometer-based driving distances and have argued against the credibility of the low-mileage bias. This paper has re-worked initial data from an early study which supported low-mileage bias, this time using odometer-based readings rather than self-reported mileage. Accepting the odometer readings at face value, the low-mileage bias remains evident, albeit at a reduced level.

Measurement of driving patterns of older adults using data logging devices with and without global positioning system capability

BACKGROUND

Methods to study driving patterns and exposure of older drivers have typically relied on surveys or driving diaries. Electronic data logging devices may offer a reliable, alternative method of measuring driving exposure, and global positioning system (GPS) technology may be able to provide further information about driving patterns.

OBJECTIVES

The aim of this study was to compare a driving diary with two electronic data logging devices, one of which had GPS capability, in order to identify which method best assesses the driving exposure and habits of older drivers as well as the method most acceptable to study participants.

METHOD

In this prospective cohort study we recruited 20 participants aged 70 years or more (mean 78; range 70-85) (15 men and 5 women). The participants' driving patterns were recorded for one week with an electronic data logging device with GPS (FleetPulse), followed by recording for a further week with an electronic data logging device without GPS (CarChip). During both time periods the subjects also completed a standard driving diary.

RESULTS

More comprehensive information, including braking and acceleration patterns, duration of driving time, time of day, and maximum speeds, was collected with the electronic devices than with the driving diary. There was excellent correlation between the driving diary data and those obtained with the CarChip (r = 0.9; p < 0.01). The correlation between the driving diary data and the FleetPulse data was moderate (r = 0.56; p = 0.02). The subjects clearly preferred the electronic monitoring devices over the driving diary. GPS data were able to demonstrate driving routes.

CONCLUSIONS

Electronic data logging devices are a valid method for recording the driving patterns of older adults. These devices also reduce burden and improve the completeness of data.